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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

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FORM 20-F

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(Mark One)

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OR

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☒ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

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For the fiscal year ended December 31, 2022

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OR

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OR

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Date of event requiring this shell company report: Not applicable

For the transition period from           to         

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Commission file number 001-36622

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PROQR THERAPEUTICS N.V.

(Exact name of Registrant as specified in its charter)

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The Netherlands

(Jurisdiction of incorporation or organization)

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Zernikedreef 9

2333 CK Leiden

The Netherlands

(Address of principal executive offices)

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Jurriaan Dekkers, Chief Financial Officer

Tel: +31 88 166 7000

jdekkers@proqr.com, Zernikedreef 9, 2333 CK Leiden, The Netherlands

(Name, Telephone, E-mail and/or Facsimile number and Address of Company Contact Person)

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Securities registered or to be registered pursuant to Section 12(b) of the Act:

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Securities registered or to be registered pursuant to Section 12(g) of the Act:

None

(Title of Class)

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Securities for which there is a reporting obligation pursuant to Section 15(d) of the Act:

None

(Title of Class)

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Indicate the number of outstanding shares of each of the issuer’s classes of capital or common stock as of the close of the period covered by the annual report.

Ordinary shares, nominal value € 0.04 per share: 80,817,079

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Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.

◻ Yes   ⌧ No

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If this report is an annual or transition report, indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934.

◻ Yes   ⌧ No

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Note – Checking the box above will not relieve any registrant required to file reports pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 from their obligations under those Sections.

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Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.

⌧ Yes   ◻ No

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Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).

⌧ Yes   ◻ No

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Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or an emerging growth company. See definition of “large accelerated filer”, “accelerated filer”, and “emerging growth company” in Rule 12b-2 of the Exchange Act. (Check one):

If an emerging growth company that prepares its financial statements in accordance with U.S. GAAP, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards† provided pursuant to section 13(a) of the Exchange Act. ◻

†The term “new or revised financial accounting standard” refers to any update issued by the Financial Accounting Standards Board to its Accounting Standards Codification after April 5, 2012.

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☒

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If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ◻

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Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b).

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Indicate by check mark which basis of accounting the registrant has used to prepare the financial statements included in this filing:

If “Other” has been checked in response to the previous question, indicate by check mark which financial statement item the registrant has elected to follow.

◻ Item 17   ◻ Item 18

If this is an annual report, indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).

☐ Yes   ⌧ No

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Summary of the Material and Other Risks Associated with Our Business

Our business is subject to numerous material risks and uncertainties that you should be aware of in evaluating our business, including those described in Part I, Item 3.D: “Risk Factors” in this Annual Report on Form 20-F, or this Annual Report. These risks include, but are not limited to, the following:

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The material and other risks summarized above should be read together with the text of the full risk factors discussed in the section entitled “Risk Factors” and the other information set forth in this Annual Report, including our consolidated financial statements and the related notes, as well as in other documents that we file with the Securities and Exchange Commission (the SEC). If any such material and other risks and uncertainties actually occur, our business, prospects, financial condition and results of operations could be materially and adversely affected. The risks summarized above or described in full elsewhere in this Annual Report are not the only risks that we face. Additional risks and uncertainties not currently known to us, or that we currently deem to be immaterial may also materially adversely affect our business, prospects, financial condition and results of operations.

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Introduction

This document contains information required for the Annual Report on Form 20-F for the year ended December 31, 2022 of ProQR Therapeutics N.V. (the Annual Report). Unless the context specifically indicates otherwise, references in this Annual Report to “ProQR Therapeutics N.V.”, “ProQR Therapeutics”, “ProQR”, “we”, “our”, “ours”, “us”, the “Company” and similar designations refer to ProQR Therapeutics N.V., a company organized under the laws of the Netherlands, and where appropriate, its consolidated subsidiaries.

IFRS Based Information

The audited financial statements as at December 31, 2022 and 2021, and for the years ended December 31, 2022, December 31, 2021 and December 31, 2020, included in the Annual Report have been prepared in accordance with International Financial Reporting Standards (IFRS) as issued by the International Accounting Standards Board (IASB).

Non-GAAP Information

In presenting and discussing our financial position, operating results and cash flows, management uses certain non-GAAP financial measures. These non-GAAP financial measures should not be viewed in isolation as alternatives to the equivalent IFRS measure and should be used in conjunction with the most directly comparable IFRS measure(s).

Exchange Rates

All references in this Annual Report to “U.S. dollars” or “$” are to the legal currency of the United States, and all references to “€” or “euro” are to the currency of the European Economic and Monetary Union. Our business to date has been conducted primarily in the European Union, and we maintain our books and records in euro. We present our financial statements in euro, which is the Company’s functional currency.

Fair Value Information

In presenting our financial position, fair values are used for the measurement of various items in accordance with the applicable accounting standards. These fair values are based on market prices, where available, and are obtained from sources that are deemed to be reliable. Readers are cautioned that these values are subject to changes over time and are only valid at the balance sheet date. When quoted prices or observable market values do not exist, fair values are estimated using valuation models, which we believe are appropriate for their purpose. They require management to make significant assumptions with respect to future developments which are inherently uncertain and may therefore deviate from actual developments. Critical assumptions used are disclosed in the financial statements. In certain cases, independent valuations are obtained to support management’s determination of fair values.

Trademarks

We use various trademarks and tradenames, including without limitation “ProQR”, “Axiomer”, “Trident” and our corporate logo, that we use in connection with the operation of our business. Other trademarks or trade names of third parties referred to or incorporated by reference in this Annual Report are the property of their respective owners. Solely for convenience, the trademarks and trade names in this Annual Report may be referred to without the ®, ™ or ^SM symbols, but such references should not be construed as any indicator that their respective owners will not assert, to the fullest extent permissible under applicable law, their rights thereto. We do not intend to use or display other companies’ trademarks and trade names to imply a relationship with, or endorsement or sponsorship of us, any other companies.

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Cautionary Language Regarding Forward-looking Statements

This Annual Report contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the Securities Act), and Section 21E of the Securities Exchange Act of 1934, as amended (the Exchange Act), that involve substantial risks and uncertainties. The forward-looking statements are contained principally in Part I, Item 4.B “Business Overview,” Part I, Item 3.D. “Risk Factors,” and Part I, Item 5. “Operating and Financial Review and Prospects,” but are also contained elsewhere in this Annual Report. Forward-looking statements can be identified generally as those containing words as “aim,” “anticipate,” “believe,” “estimate,” “expect,” “intend,” “may,” “plan,” “predict,” “project,” “target,” “potential,” “will,” “would,” “could,” “should,” “continue,” or the negative of these terms, or other comparable terminology intended to identify statements about the future, although not all forward-looking statements contain these identifying words. These statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, levels of activity, performance or achievements to be materially different from the information expressed or implied by these forward-looking statements. The forward-looking statements contained in this Annual Report are based upon information available to us as of the date of this Annual Report and, while we believe we have a reasonable basis for each forward-looking statement contained this Annual Report, we caution you that these statements are based on a combination of facts and factors currently known by us and our expectations of the future, about which we cannot be certain.

By their nature, forward-looking statements involve risks and uncertainties because they relate to events, competitive dynamics and industry change, and depend on economic circumstances that may or may not occur in the future or may occur on longer or shorter timelines than anticipated. Although we believe that we have a reasonable basis for each forward-looking statement contained in this Annual Report, we caution you that forward-looking statements are not guarantees of future performance and involve known and unknown risks, uncertainties and other factors that are in some cases beyond our control. Known and unknown risks, uncertainties and other factors may cause our actual results, performance or achievements, including in relation to the research and (pre-) clinical development of sepofarsen (formerly known as QR-110), ultevursen (formerly known as QR-421a), or our RNA editing platforms or any of our pipeline programs, to be materially different from our expectations. These forward-looking statements include, without limitation, statements about the following:

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In addition, even if our results, performance, financial condition and liquidity, and the development of the industry in which we operate are consistent with such forward-looking statements, they may not be predictive of results or developments in future periods. Among the factors that may result in differences are our expectations regarding risks and uncertainties related to the impact of the ongoing COVID-19 pandemic on our business, operations, strategy, goals and anticipated milestones, including our ongoing and planned research activities, ability to conduct ongoing and planned clinical trials, clinical supply of current or future drug candidates, commercial supply of current or future approved products, and launching, marketing and selling current or future approved products, and our ability to obtain and maintain requisite regulatory approvals and to enroll patients in our planned clinical trials, additional interactions with regulatory authorities and expectations regarding future regulatory filings, our reliance on collaborations with third parties, estimating the commercial potential of our development programs and other risks indicated in the risk factors included in this report and other filings with the U.S. Securities and Exchange Commission, or the SEC.

Actual results could differ materially from our forward-looking statements due to a number of factors, including the risks set forth under the section “Risk Factors” of this report and elsewhere in this Annual Report.

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Any forward-looking statements that we make in this Annual Report are valid only as of the date of such statements, and we undertake no obligation to update such statements to reflect events or circumstances after the date of this Annual Report or to reflect the occurrence of unanticipated events.

This Annual Report contains market data and industry forecasts that were obtained from industry publications. These data involve a number of assumptions and limitations, and you are cautioned not to give undue weight to such estimates. While we believe the market position, market opportunity and market size information included in this Annual Report is generally reliable, such information is inherently imprecise.

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Part I

Item 1: Identity of Directors, Senior Management and Advisers

Not applicable.

Item 2: Offer Statistics and Expected Timetable

Not applicable.

Item 3: Key Information

A. [Reserved]

Not applicable.

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B. Capitalization and Indebtedness

Not applicable.

C. Reasons for the Offer and Use of Proceeds

Not applicable.

D. Risk Factors

You should consider carefully the risks and uncertainties described below, together with all of the other information in this Annual Report, including the financial statements and the related notes included elsewhere in this Annual Report. The risks and uncertainties described below are not the only ones we face. Additional risks and uncertainties that we are unaware of, or that we currently believe are not material, may also become important factors that adversely affect our business. If any of the following risks actually occurs, our business, financial condition, results of operations, and future prospects could be materially and adversely affected.

Risks Related to Our Capital Needs and Financial Position

We are a biopharmaceutical company with a history of losses. We expect to continue to incur significant losses for the foreseeable future and may never achieve or maintain profitability, which could result in a decline in the market value of our ordinary shares.

We are a biopharmaceutical company with a limited operating history, engaged in the discovery and development of RNA-based therapeutics with our proprietary RNA editing platforms technology which could be used to develop new product candidates across multiple therapeutic areas. Since our inception in February 2012, we have devoted a significant portion of our resources to the development of our product candidates in inherited retinal disorders, including sepofarsen for Leber Congenital Amaurosis (LCA), ultevursen for Usher syndrom, and QR-1123 for autosomal dominant retinitis pigmentosa. Past resources have also been expended for the development of QR-504a for Fuchs endothelial corneal dystrophy, and eluforsen for cystic fibrosis, for which we have ceased making investments, and QR-313 for epidermolysis bullosa, which we have spun off. In August 2022 we announced our strategy to exclusively focus our resources on the development of our RNA editing platforms. As a result, we have ended the clinical development of sepofarsen and ultevursen, as well as the development of QR-1123 and QR-504a, for which we are currently seeking a partner to develop these programs. However, there can be no assurance that we will secure a partnership for the development of any of these product candidates. We have had significant operating losses since our inception. Our net losses for the years ended December 31, 2022, December 31, 2021 and December 31, 2020 were, € 64,891,000, € 61,680,000 and € 46,614,000 respectively. At December 31, 2022, we had an accumulated deficit of € 380,677,000. Substantially all of our losses have resulted from expenses incurred in connection with our research and development programs and from general and administrative costs associated with our operations. Our RNA editing platforms are still

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in early stages of development and we are subject to the risks of failure inherent in the development of novel technologies and product candidates based on novel technologies.

To date, the only material income we have generated has been from the receipt of government research grants and collaboration agreements. Our ability to generate revenue from product sales depends upon our ability to successfully develop candidates with our RNA editing platform, subsequently obtain regulatory approval for these candidates and successfully commercialize them and any other product candidates that we might develop, in-license or acquire in the future, enter into new collaboration agreements and generate milestone and royalty payments under existing or future collaboration agreements.

Even if we are able to successfully achieve regulatory approval for our product candidates, we do not know when any of these product candidates will generate revenue for us, if at all. We have not generated, and do not expect to generate, any product revenue for the foreseeable future, and we expect to continue to incur significant operating losses for the foreseeable future due to the cost of research and development of both RNA editing platforms and product candidates, preclinical studies and clinical trials and the regulatory approval process for product candidates. The amount of future losses is uncertain. Our ability to achieve profitability, if ever, will depend on, among other things, our ability to develop product candidates with our RNA editing platforms, us or any current or future collaborators successfully developing product candidates, obtaining regulatory approvals to market and commercialize product candidates, manufacturing any approved products on commercially reasonable terms, establishing a sales and marketing organization or suitable third party alternatives for any approved product and raising sufficient funds to finance business activities. If we or any current or future collaborators are unable to develop and commercialize one or more of our product candidates or if sales revenue from any product candidate that receives approval is insufficient, we will not achieve profitability, which could have a material adverse effect on our business, financial condition, results of operations and prospects.

Our ability to generate revenue from our product candidates also depends on a number of additional factors, including our ability to:

In addition, because of the numerous risks and uncertainties associated with product development, including the risk that our product candidates may not advance through development, as has been the case for product candidates for which we have suspended or ceased development activities, or be shown not to be safe and effective for their intended uses, the FDA, the EMA or other regulatory agencies may require additional clinical trials or preclinical studies or impose post-approval requirements for product candidates that do advance through development.

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We are unable to predict the timing or amount of increased expenses, or when or if we will be able to achieve or maintain profitability. Even if we are able to complete the processes described above, we anticipate incurring significant costs associated with commercializing our product candidates.

In view of our intention to partner ultevursen for further development, commitments pursuant to our agreement with the Foundation Fighting Blindness (FFB) might trigger royalty payments of up to $ 33.8 million, partly upon partnering and partly upon commercialization. Furthermore, the partnering of ultevursen shall require such partner to commit itself to similar undertakings and assume joint and several liability for at least part of the royalty undertaking towards FFB. See “Item 5. Operating and Financial Review and Prospects” and the notes to the financial statements included elsewhere in this annual report for more details on these transactions.

Even if we are able to generate revenues from the sale of any of our product candidates or if will receive royalties from of our collaboration partners, we may not become profitable and may need to obtain additional funding to continue operations. If we fail to become profitable or are unable to sustain profitability on a continuing basis, then we may be unable to continue our operations at planned levels and be forced to reduce our operations, which could result in a decline in the market value of our ordinary shares.

We will require additional capital to fund our operations and if we fail to obtain necessary financing, we will not be able to complete the development and commercialization of our product candidates.

Our operations have consumed substantial amounts of cash since inception. We expect to continue to spend substantial amounts of cash to conduct further research and development, including with respect to our Axiomer platform, and preclinical testing and clinical trials of our product candidates, to seek regulatory approvals for our product candidates and to launch and commercialize any product candidates for which we receive regulatory approval, including potentially building our own commercial organization to serve the United States, the European Union and certain other markets. As at December 31, 2022, we had € 94,775,000 in cash and cash equivalents. Based on our current operating plans announced as part of our strategy update in August 2022, we believe that such existing cash and cash equivalents will be sufficient to fund our anticipated level of operations into 2026. However, our future capital requirements and the period for which our existing resources will support our operations may vary significantly from what we expect. Our monthly spending levels will vary based on new and ongoing development and corporate activities. Because the length of time and activities associated with successful development of our RNA editing platforms and product candidates is highly uncertain, we are unable to estimate the actual funds we will require for development and any approved marketing and commercialization activities relating to product candidates. Our future funding requirements, both near and long-term, will depend on many factors, including, but not limited to:

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We cannot be certain that additional funding will be available on acceptable terms, or at all. If we are unable to raise additional capital in sufficient amounts or on terms acceptable to us, we may have to significantly delay, scale back or discontinue the development or commercialization of one or more of our products or product candidates or one or more of our other research and development initiatives such as our RNA editing platforms. In order to raise additional capital, we may seek a combination of private and public equity offerings, debt financings, strategic partnerships and alliances and licensing arrangements. To the extent that we raise additional capital through the sale of equity or convertible debt securities, existing ownership interests may be diluted and the terms of such financings may include liquidation or other preferences that adversely affect the rights of existing shareholders. We also could be required to seek collaborators for one or more of our current or future product candidates at an earlier stage than otherwise would be desirable or on terms that are less favorable than might otherwise be acceptable or relinquish or license on unfavorable terms our rights to technologies or product candidates that we otherwise would seek to develop or commercialize ourselves.

While we were founded in 2012, we recently announced our plans to refocus our business on our RNA editing platforms, and it may be difficult to assess the future viability of our business and our strategy.

We were founded in February 2012 and began operations in May 2012, since which time we have primarily focused our efforts on development activities for our product candidates, including acquiring and developing product and technology rights and entering into collaborations. We have revised our strategy from time to time, including most recently in August 2022 when we announced our plan to focus exclusively on our RNA editing platforms, therewith withdrawing from the ophthalmology space. Consequently, any predictions about our future success, performance or viability may not be as accurate as they could be if we had a longer operating history, more experience with research and development initiatives and clinical development or approved products on the market.

We or third parties upon whom we depend may be adversely affected by natural disasters and/or global health pandemics, and our business, financial condition and results of operations could be adversely affected.

The occurrence of unforeseen or catastrophic events, including extreme weather events and other natural disasters, man-made disasters, or the emergence of epidemics or pandemics, depending on their scale, may cause different degrees of damage to the national and local economies and could cause a disruption in our operations and have a material adverse effect on our financial condition and results of operations. Man-made disasters, pandemics, and other events connected with the regions in which we operate could have similar effects. If a natural disaster, health pandemic, or other event beyond our control occurred that prevented us from using all or a significant portion of our office and/or lab spaces, damaged critical infrastructure, such as our manufacturing facilities or our manufacturing facilities of our third-party contract manufacturers, or that otherwise disrupted operations or supplies, it may be difficult for us to continue our business for a substantial period of time.

The effects of the COVID-19 pandemic may materially and adversely affect our business and our financial results.

The continued effects of the COVID-19 pandemic could adversely impact our clinical trials or preclinical studies, including our ability to recruit and retain patients and principal investigators and site staff who, as healthcare providers, have heightened exposure to COVID-19. While we have implemented mitigation procedures designed to enable us to continue our development activities, there can be no assurance that these procedures will continue to be successful or that we can avoid a material and adverse disruption to our business in case further spikes in the number of infections, including due to the emergence of new variants, would occur in countries where patients are expected to be enrolled or where they are located. If the number of cases were to sharply increase, we could expect the prioritization of hospital resources toward the treatment of COVID-19 patients and restrictions in travel. Furthermore, persons living with indications that are targeted by ProQR’s future product candidates may be unwilling to enroll in our trials or be unable to comply with clinical trial protocols if new quarantines or travel restrictions were to impede patient movement or interrupt healthcare services. COVID-19 restrictions can also negatively affect the operations of third-party contract research organizations (CROs) that we rely upon to carry out our clinical trials. Moreover, COVID-19 might impact the

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operations of our third-party manufacturers, which could result in delays or disruptions in the supply of our product candidates. Since the beginning of the COVID-19 pandemic, several vaccines for COVID-19 have received Emergency Use Authorization by the FDA and a number of these later received marketing approval. Additional vaccines may be authorized or approved in the future. The resultant demand for vaccines and potential for manufacturing facilities and materials to be commandeered under the Defense Production Act of 1950, or equivalent foreign legislation, may make it more difficult to obtain materials or manufacturing slots for the products needed for our clinical trials, which could lead to delays in these trials. While we do not currently believe our supply chain has been affected, there can be no assurances that we will not experience supply disruptions in the future. The negative impact COVID-19 has had and may continue to have to patient enrollment or treatment or the timing and execution of clinical trials could cause costly delays to our future clinical trial activities, which could adversely affect our ability to obtain regulatory approval for and to commercialize our future product candidates, increase our operating expenses and have a material adverse effect on our business and financial results.

In addition, COVID-19 resulted in significant governmental measures being implemented to control the spread of the virus, including quarantines, travel restrictions and business shutdowns. If the number of cases again sharply increases, we could expect similar governmental measures. We have taken and may again need to take temporary precautionary measures intended to help minimize the risk of the virus to our employees, including requiring most of our employees to work remotely, suspending all non-essential travel worldwide for our employees and attending industry events and work-related meetings remotely. These measures could negatively affect our business. For instance, requiring employees to work remotely may result in decreased efficiency and effectiveness of our operations and increases the risk of a cybersecurity incident. COVID-19 has also caused volatility in the global financial markets and threatened a slowdown in the global economy, which could negatively affect our ability to raise additional capital on attractive terms or at all.

The extent to which COVID-19 continues to impact our business, results of operations and financial condition will depend on future developments, which are highly uncertain and cannot be predicted with confidence, such as the occurrence of a new outbreak, new information that may emerge concerning the severity of COVID-19, new strains of the virus that may emerge, which may impact rates of infection and vaccination efforts, developments or perceptions regarding the safety of vaccines, or the extent and effectiveness of actions to contain COVID-19 and treat its impact, including vaccination campaigns and lockdown measures, among others. In addition, recurrences or additional waves of COVID-19 cases could cause other widespread or more severe impacts depending on where infection rates are highest. We cannot presently predict the scope and severity of any potential business shutdowns or disruptions, but if we or any of the third parties with whom we engage were to experience prolonged business shutdowns or other disruptions, our ability to conduct our business in the manner and on the timelines presently planned could be materially and negatively affected, which could have a material adverse impact on our business, results of operation and financial condition.

Risks Related to the Development and Regulatory Approval of our Product Candidates

Our business depends in part on the success of our product candidates. We cannot be certain that we will be able to successfully complete the clinical development of, obtain regulatory approval for, or successfully commercialize our product candidates.

Our business depends in part on our ability to develop, secure regulatory approval for and commercialize one or more product candidates, including any product candidates resulting from our initial pipeline programs using our Axiomer technology, including AX-0810 for Cholestatic Diseases targeting NTCP and AX-1412 for Cardiovascular Disease targeting B4GALT1. However, the development of drug candidates is lengthy, uncertain and expensive, and there can be no assurance that we will achieve such goals. For example, in the past, we have focused our efforts on the development of product candidates in our ophthalmology portfolio and, previously, for cystic fibrosis, none of which we are planning to continue developing at this time. In February 2022, we announced that top-line results from our Phase 2/3 pivotal trial of sepofarsen did not meet its primary endpoint.

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In addition, as part of our strategy update in April 2022, we suspended the early phase clinical trials for our QR-1123 program for autosomal dominant retinitis pigmentosa (adRP) and our QR-504a program for Fuchs endothelial corneal dystrophy and suspended all other research activities related to our inherited retinal disease pipeline. In August 2022, we announced our strategy to shift our focus and resources exclusively to the development of our RNA editing platforms,

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therewith ending the clinical development of sepofarsen and ultevursen while seeking a partner to further continue these programs, and therewith ultimately ending all activity related to the broader ophthalmology portfolio.

The clinical trials and manufacturing and marketing of our future product candidates will be subject to extensive and rigorous review and regulation by numerous government authorities in the United States, the European Union and other jurisdictions where we intend to test and, if approved, market our product candidates. Before obtaining regulatory approvals for the commercial sale of any product candidate, we must demonstrate through preclinical testing and clinical trials that the product candidate is safe and effective for use in each target indication, and potentially in specific patient populations, including the pediatric population. This process can take many years and may include post-marketing studies and surveillance, which would require the expenditure of substantial resources beyond our existing funds. Of the large number of drugs in development for approval in the United States and the European Union, only a small percentage successfully complete the FDA or EMA regulatory approval processes, as applicable, and are commercialized. Accordingly, even if we are able to obtain the requisite financing to continue to fund our research, development and clinical programs, we cannot be certain that any of our product candidates will be successfully developed or commercialized.

In addition, if a third party collaborator were to resume the advancement of sepofarsen, ultevursen, QR-1123 or QR-504a, or commence new clinical programs of our product candidates in the future, the successful clinical development, regulatory approval and commercialization of any of these product candidates would require additional or new preclinical and clinical testing and substantial additional or new clinical development and regulatory approval efforts before we are permitted to commence their commercialization, if ever. It would be several years before a pivotal trial could be completed for any of such other product candidates, if ever.

We may not be able to file investigational new drug applications (INDs) or IND amendments or similar applications to commence clinical trials of our product candidates on the timelines we expect, and even if we are able to, the FDA or similar foreign regulatory authority may not permit us to proceed.

We may not be able to file INDs or similar applications for our product candidates on the timelines we expect. For example, we may experience manufacturing delays or other delays with IND-enabling studies. Moreover, we cannot be sure that submission of an IND or similar application will result in the FDA or similar foreign regulatory authority allowing clinical trials to begin, or that, once begun, issues will not arise that result in the suspension or termination of clinical trials. Additionally, even if such regulatory authorities agree with the design and implementation of the clinical trials set forth in an IND or similar application, we cannot guarantee that such regulatory authorities will not change their requirements in the future. These considerations apply to new clinical trials we may submit as amendments to existing INDs or to a new IND or similar application. Any failure to file INDs or similar applications on the timelines we expect or to obtain authorization to begin our trials may prevent us from completing our clinical trials or commercializing our products on a timely basis, if at all.

The regulatory approval processes of the FDA, the EMA and comparable foreign regulatory authorities are lengthy, time-consuming and inherently unpredictable, and if we are ultimately unable to obtain regulatory approval for our product candidates, our business will be substantially harmed.

We are not permitted to market our product candidates in the United States or the European Union until we receive an NDA approval from the FDA or an MAA approval from the European Commission, respectively, or in any other foreign countries until we receive the requisite approval from such countries. Prior to submitting an NDA to the FDA or an MAA to the EMA for approval of any product candidate, we will need to complete preclinical and toxicology studies, as well as proof-of-concept studies and Phase 1, Phase 2 and Phase 3 clinical trials for such candidate. While we intend to submit marketing applications for our product candidates that successfully complete clinical development, there can be no assurance that we will be able to do so in a timely manner or at all. Successfully initiating and completing clinical programs and obtaining approval of an NDA or a MAA is a complex, lengthy, expensive and uncertain process, and the FDA, the EMA or other comparable foreign regulatory authorities may delay, limit or deny approval of our product candidates for many reasons, including, among others:

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Any of these factors, many of which are beyond our control, could jeopardize our ability to obtain regulatory approval for and successfully market our product candidates. Any such setback in our pursuit of regulatory approval would have a material adverse effect on our business and prospects.

We may never realize a return on our investment of resources and cash from our drug discovery collaborations.

In addition to developing our own pipeline of product candidates, we also conduct drug discovery activities for or with collaborators who are also engaged in drug discovery and development, which could include pre-commercial biotechnology companies and large pharmaceutical companies. Under these collaborations, we might provide the benefit of our drug discovery platforms and platform experts who identify molecules that have activity against one or more specified targets, among other resources. In consideration, we have received, and might receive in the future, (i) equity investments; (ii) upfront fees; and/or (iii) the right to receive option fees, cash milestone payments upon the achievement of specified development, regulatory, or commercial sales milestones for the drug discovery targets, and potential royalties. Our ability to receive fees and payments and realize returns from our drug discovery collaborations in a timely manner, or at all, is subject to a number of risks, including but not limited to the following:

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Failures or delays in the commencement or completion of our preclinical studies or planned or future clinical trials of our future product candidates could result in increased costs to us and could delay, prevent or limit our ability to generate revenue and continue our business.

Successful completion of preclinical studies and clinical trials is a prerequisite to submitting an NDA to the FDA or an MAA to the EMA and, consequently, the ultimate approval and commercial marketing of our product candidates. Clinical trials are expensive, difficult to design and implement, can take many years to complete and are uncertain as to outcome. A product candidate can unexpectedly fail at any stage of clinical development. The historical failure rate for product candidates is high due to scientific feasibility, safety, efficacy, changing standards of medical care and other variables. We do not know whether our future clinical trials will begin or be completed on schedule, if at all, as the commencement and completion of clinical trials can be delayed or prevented for a number of reasons, including, among others:

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Clinical trials may also be delayed or terminated as a result of ambiguous or negative interim results. In addition, a clinical trial may be suspended or terminated by us, the FDA, the EMA, the IRBs at the sites where the IRBs are overseeing a clinical trial, upon recommendation of a data safety monitoring board (DSMB) overseeing the clinical trial at issue, or by other regulatory authorities due to a number of factors, including, among others:

Positive results from early-stage clinical trials and preclinical testing of our future product candidates are not necessarily predictive of the results of later clinical trials for these product candidates. If we cannot achieve positive results in our later stage clinical trials for our product candidates, we may be unable to successfully develop, obtain regulatory approval for and commercialize them.

We may from time to time publish results from preclinical studies and clinical trials of our product candidates. Positive results from early-stage clinical trials and preclinical testing of our product candidates in vitro and in vivo may not necessarily be predictive of the results from later-stage clinical trials. Many companies in the pharmaceutical and biotechnology industries have suffered significant setbacks in later-stage clinical trials after achieving positive results in preclinical and early-stage clinical trials, and we cannot be certain that we will not face similar setbacks. These setbacks have been caused by, among other things, preclinical findings made while clinical trials were already underway or safety or efficacy observations made in clinical trials, including adverse events. Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses, and many companies that believed their product candidates performed satisfactorily in preclinical studies and clinical trials nonetheless failed to obtain FDA or EMA approval. If we fail to produce positive results in our clinical trials for any product candidates, the development timeline and regulatory approval and commercialization prospects for those product candidates, and, correspondingly, our business and financial prospects would be materially adversely affected.

Additionally, some of our clinical trials have utilized and may in the future utilize an “open-label” trial design. An “open-label” clinical trial is one where both the patient and investigator know whether the patient is receiving the investigational product candidate or either an existing approved drug or placebo. Most typically, open-label clinical trials

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test only the investigational product candidate and sometimes may do so at different dose levels. Open-label clinical trials are subject to various limitations that may exaggerate any therapeutic effect as patients in open-label clinical trials are aware when they are receiving treatment. Open-label clinical trials may be subject to a “patient bias” where patients perceive their symptoms to have improved merely due to their awareness of receiving an experimental treatment. Moreover, patients selected for early clinical studies often include the most severe sufferers and their symptoms may have been bound to improve notwithstanding the new treatment. In addition, open-label clinical trials may be subject to an “investigator bias” where those assessing and reviewing the physiological outcomes of the clinical trials are aware of which patients have received treatment and may interpret the information of the treated group more favorably given this knowledge. The results from an open-label trial may not be predictive of future clinical trial results with any of our product candidates when studied in a controlled environment with a placebo or active control.

Changes in regulatory requirements or guidance from the FDA, EMA or other applicable regulatory authorities, or unanticipated events during our preclinical or clinical development activities may occur, which may result in changes to requirements, which could result in increased costs to us and could delay our development timeline.

Changes in regulatory requirements, or guidance from the FDA, EMA, or other applicable regulatory authorities, imposition of additional preclinical or clinical study requirements by applicable regulatory authorities or unanticipated events during our preclinical or clinical development may force us to amend study protocols or conduct additional studies or trials or involve delays to our preclinical and clinical studies and overall development strategy, all of which could result in increased costs for the development of our product candidates. We may experience delays if we are required by the FDA, EMA, or other applicable regulatory authorities, or if we voluntarily decide to, redesign or restructure a clinical trial once initiated. Amendments to our clinical trial protocols may require resubmission to the applicable regulatory authorities and IRBs or ethics committees for review and approval, which may adversely impact the cost, timing and/or successful completion of a clinical trial. We may be delayed in our clinical development if we are unable to obtain alignment with the FDA, EMA, or other applicable regulatory authorities on an acceptable clinical trial design or statistical analysis plan for any of our clinical trials. Additionally, the FDA, EMA, or other applicable regulatory authorities may require us to conduct additional clinical trials, including pivotal trials, to support a marketing application. If we experience delays completing, or if we terminate, any of our clinical trials, or if we are required to conduct additional clinical trials, the commercial prospects for our product candidates may be harmed and our ability to generate product revenue will be delayed.

Our RNA technologies are unproven in the disease indications for which they are being developed and tested and may not lead to the development of, or result in, marketable products.

We are developing RNA editing platforms and a pipeline of product candidates using these proprietary RNA technologies for genetic disorders with unmet need. We believe that targeting the mRNA to restore the production of functional protein is a unique approach that offers advantages versus small molecule, gene therapy and other therapeutic approaches. However, the scientific research that forms the basis of our efforts to develop product candidates is both preliminary and limited. The mechanism of action of our compounds could be different from what we today hypothesize. Also, we may discover that the molecules that we develop do not possess certain properties required for a drug to be effective, such as the ability to remain stable in the human body for the period of time required for the drug to reach the target tissue or the ability to cross the cell wall and enter into cells within the target tissue for effective delivery. We may spend substantial funds attempting to introduce these properties and may never succeed in doing so. For example, while we have discovered and are developing our novel RNA editing platforms and will focus our resources exclusively on these RNA editing platforms as announced as part of our strategy update in August 2022, there can be no assurance that we will be able to leverage our technology to create viable product candidates to advance into the clinic, or develop those candidates to submit for regulatory approval. In addition, product candidates based on RNA technologies may demonstrate different chemical and pharmacological properties in humans than they do in laboratory studies or animals. Even if our product candidates have successful results in animal studies, they may not demonstrate the same chemical and pharmacological properties in humans and may interact with human biological systems or other existing treatments in unforeseen, ineffective or harmful ways. Our RNA technologies may provoke an unwanted immune response, or immunogenicity, which may neutralize the therapeutic effects of our product candidates and could result in harmful outcomes for patients. As a result, we may never succeed in developing a marketable product, and in turn we may not become profitable and the value of our ordinary shares would decline.

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While there are a number of approved therapies based on the oligonucleotide modality, there are no approved therapies based on the editing technology underlying our novel editing mechanism which uses ADAR. This may increase the complexity, uncertainty and length of the regulatory approval process for our product candidates. Neither we nor any future collaborator may receive approval to market and commercialize any product candidate. Even if we or a collaborator were to obtain regulatory approval, the approval may be for disease indications or patient populations that are not as broad as we intended or may require labeling that includes significant use or distribution restrictions or safety warnings. We or a collaborator may be required to perform additional or unanticipated clinical trials to obtain approval or be subject to post-marketing testing requirements to maintain regulatory approval. If our RNA technology proves to be ineffective, unsafe or commercially unviable, our entire platforms and pipeline would have little, if any, value, which would have a material adverse effect on our business, financial condition, results of operations and prospects.

Failure to obtain regulatory approval in jurisdictions outside the United States and the European Union would prevent our product candidates from being marketed in those jurisdictions.

In order to market and sell our products in jurisdictions other than the United States and the European Union, we must obtain separate marketing approvals and comply with numerous and varying regulatory requirements. The regulatory approval process outside the United States and the European Union generally includes all of the risks associated with obtaining FDA and EMA approval, but can involve additional testing. We may need to partner with third parties in order to obtain approvals outside the United States and the European Union. In addition, in many countries worldwide, it is required that the product be approved for reimbursement before the product can be approved for sale in that country. We may not obtain approvals from regulatory authorities outside the United States and the European Union on a timely basis, if at all. Even if we were to receive approval in the United States or the European Union, approval by the FDA or the EMA does not ensure approval by regulatory authorities in other countries or jurisdictions. Similarly, approval by one regulatory authority outside the United States and the European Union would not ensure approval by regulatory authorities in other countries or jurisdictions or by the FDA or the EMA. We may not be able to file for marketing approvals and may not receive necessary approvals to commercialize our products in any market. If we are unable to obtain approval of our product candidates by regulatory authorities in other foreign jurisdictions, the commercial prospects of those product candidates may be significantly diminished and our business prospects could decline.

A breakthrough therapy designation by the FDA for our product candidates may not lead to a faster development or regulatory review or approval process, and it does not increase the likelihood that our product candidates will receive marketing approval.

We may seek a breakthrough therapy designation for our product candidates in the future. A breakthrough therapy is defined as a drug that is intended, alone or in combination with one or more other drugs, to treat a serious or life-threatening disease or condition, and preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over available therapies on one or more clinically significant endpoints. For product candidates that have been designated as breakthrough therapies, interaction and communication between the FDA and the sponsor of the trial can help to identify the most efficient path for clinical development while minimizing the number of patients placed in ineffective control regimens. Product candidates designated as breakthrough therapies by the FDA may also be eligible for accelerated approval.

Designation as a breakthrough therapy is within the discretion of the FDA. Accordingly, even if we believe that any of our product candidates meets the criteria for designation as a breakthrough therapy, the FDA may disagree and instead determine not to make such designation. The availability of breakthrough therapy designation was established with the passage of the Food and Drug Administration Safety and Innovation Act of 2012, and while the FDA has released guidance as to the criteria it uses in designating drugs as breakthrough therapies, we cannot be sure that our product candidates will meet the FDA’s qualifying criteria for such designation. In any event, the receipt of a breakthrough therapy designation for a product candidate may not result in a faster development process, review or approval compared to drugs considered for approval under conventional FDA procedures and also does not assure ultimate approval by the FDA. In addition, even if one or more of our product candidates qualify as breakthrough therapies, the FDA may later decide that the products no longer meet the conditions for such qualification or decide that the time period for FDA review or approval will not be shortened.

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We may seek designation for our Axiomer RNA editing platform as a designated platform technology, but we might not receive such designation, and even if we do, such designation may not lead to a faster development, regulatory review or approval process.

We may seek designation for our Axiomer RNA editing platform as a designated platform technology. Under the Food and Drug Omnibus Reform Act of 2022 (FDORA), a platform technology incorporated within or utilized by a drug or biological product is eligible for designation as a designated platform technology if (1) the platform technology is incorporated in, or utilized by, a drug approved under an NDA or BLA; (2) preliminary evidence submitted by the sponsor of the approved or licensed drug, or a sponsor that has been granted a right of reference to data submitted in the application for such drug, demonstrates that the platform technology has the potential to be incorporated in, or utilized by, more than one drug without an adverse effect on quality, manufacturing, or safety; and (3) data or information submitted by the applicable person indicates that incorporation or utilization of the platform technology has a reasonable likelihood to bring significant efficiencies to the drug development or manufacturing process and to the review process. A sponsor may request the FDA to designate a platform technology as a designated platform technology concurrently with, or at any time after, submission of an IND application for a drug that incorporates or utilizes the platform technology that is the subject of the request. If so designated, the FDA may expedite the development and review of any subsequent original NDA or BLA for a drug that uses or incorporates the platform technology. Even if we believe our Axiomer platform meets the criteria for such designation, the FDA may disagree and instead determine not to grant such designation. In addition, the receipt of such designation for a platform technology does not ensure that a drug will be developed more quickly, be reviewed by the FDA faster, or receive FDA approval. Moreover, the FDA may revoke a designation if the FDA determines that a designated platform technology no longer meets the criteria for such designation.

Our therapeutic candidates are based on a novel mechanism of action, which makes it difficult to predict the time and cost of development and of subsequently obtaining regulatory approval, if at all.

Although we have discovered and are developing our novel RNA editing platforms and will focus our resources exclusively on these RNA editing platforms, as announced as part of our strategy update in August 2022, there can be no assurance that we will be able to leverage our technology to create viable product candidates to advance into the clinic, or develop those candidates to submit for regulatory approval. In addition, product candidates based on RNA technologies may demonstrate different chemical and pharmacological properties in humans than they do in laboratory studies or animals. Even if our product candidates have successful results in animal studies, they may not demonstrate the same chemical and pharmacological properties in humans and may interact with human biological systems or other existing treatments in unforeseen, ineffective or harmful ways. Our RNA technologies may provoke an unwanted immune response, or immunogenicity, which may neutralize the therapeutic effects of our product candidates and could result in harmful outcomes for patients. As a result, we or our partners may never succeed in developing a marketable product based on our platforms, and in turn we may not become profitable and the value of our ordinary shares would decline.

Furthermore, the FDA and the EMA have relatively limited experience with therapeutics based on RNA. This may increase the complexity, uncertainty and length of the regulatory approval process for our product candidates. Neither we nor any future collaborator may receive approval to market and commercialize any product candidate. Even if we or a collaborator were to obtain regulatory approval, the approval may be for disease indications or patient populations that are not as broad as we intended or may require labeling that includes significant use or distribution restrictions or safety warnings. We, or a collaborator, may be required to perform additional or unanticipated clinical trials to obtain approval or be subject to post-marketing testing requirements to maintain regulatory approval. If our RNA technology proves to be ineffective, unsafe or commercially unviable, our entire platforms and pipeline would have little, if any, value, which would have a material adverse effect on our business, financial condition, results of operations and prospects.

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Risks Related to Our Dependence on Third Parties

If a collaborative partner terminates or fails to perform its obligations under an agreement with us, the commercialization of our product candidates, if approved, could be delayed or terminated.

We are party to, and we may from time to time in the future pursue, collaborative arrangements for the development and commercialization of product candidates, if approved. We have executed and continue to consider strategic alternatives that include spinouts, out-licensing or collaborative partnerships to develop and commercialize our RNA technologies, including our Axiomer program, or programs. For example, in 2021, we entered into a licensing and research collaboration agreement with Eli Lilly and Company (Lilly), as amended in 2022 which expanded our collaboration, focused on the discovery, development, and commercialization of potential new medicines primarily in the peripheral nervous system and central nervous system and metabolic diseases. If any of our collaborative partners in future collaborative arrangements for the commercialization of product candidates or similar arrangements does not devote sufficient time and resources to the collaboration arrangement with us, we may not realize the potential commercial benefits of the arrangement, and our results of operations may be materially adversely affected. In addition, if any such collaboration partner were to breach or terminate its arrangements with us, the commercialization of our product candidates could be delayed, curtailed or terminated.

Much of the potential revenue from current and future collaborations may consist of contingent payments, such as payments for achieving regulatory milestones or royalties payable on sales of drugs. The milestone and royalty revenue that we may receive under these collaborations will depend upon our collaborators’ ability to successfully develop, introduce, market and sell new products. In addition, collaborators may decide to enter into arrangements with third parties to commercialize products developed under collaborations using our technologies, which could reduce the milestone and royalty revenue that we may receive, if any. Future collaboration partners may fail to develop or effectively commercialize products using our products or technologies because they:

Moreover, competition may negatively impact a partner’s focus on, and commitment to, our product candidates and, as a result, could delay or otherwise negatively affect the commercialization of such product candidate. The failure of any current or future collaboration partners to develop or effectively commercialize our product candidates, if approved, for any of these reasons would have a material adverse effect on our operating results and financial condition.

We rely on third-party manufacturers and suppliers and we intend to rely on third parties to produce preclinical, clinical and commercial supplies of our product candidates.

We rely on third parties to supply the materials and components for, and manufacture, our research and development, preclinical and clinical trial supplies. We do not own manufacturing facilities or supply sources for such components and materials. There can be no assurance that our supply of research and development, preclinical and clinical development drugs and other materials will not be limited, interrupted, restricted in certain geographic regions or of satisfactory quality or continue to be available at acceptable prices. In particular, any replacement of our drug product formulation manufacturer could require significant effort and expertise because there may be a limited number of qualified replacements.

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The manufacturing process for a product candidate is subject to FDA, EMA and other foreign regulatory authority review. Suppliers and manufacturers must meet applicable manufacturing requirements and undergo rigorous facility and process validation tests required by regulatory authorities in order to comply with regulatory standards such as cGMP. In the event that any of our suppliers or manufacturers fails to comply with such requirements or fails to perform its obligations to us in relation to quality, timing or otherwise, or if our supply of components or other materials becomes limited or interrupted for other reasons, we may be forced to manufacture the materials ourselves, for which we currently do not have the capabilities or resources, or enter into an agreement with another third party, which we may not be able to do on reasonable terms, if at all. In some cases, the technical skills or technology required to manufacture our product candidates may be unique or proprietary to the original manufacturer and we may have difficulty, or there may be contractual restrictions prohibiting us from, transferring such skills or technology to another third party and a feasible alternative may not exist. These factors would increase our reliance on such manufacturer or require us to obtain a license from such manufacturer in order to have another third party manufacture our product candidates. If we are required to change manufacturers for any reason, we will be required to verify that the new manufacturer maintains facilities and procedures that comply with quality standards and with all applicable regulations and guidelines. We will also need to verify, such as through a manufacturing comparability study, that any new manufacturer or manufacturing process will produce our product candidate according to the specifications previously submitted to the FDA, the EMA or another regulatory authority. The delays associated with the verification of a new manufacturer or manufacturing process could negatively affect our ability to develop product candidates in a timely manner or within budget.

We expect to continue to rely on third party manufacturers if we receive regulatory approval for any product candidate. To the extent that we have existing, or enter into future, manufacturing arrangements with third parties, we will depend on these third parties to perform their obligations in a timely manner consistent with contractual and regulatory requirements, including those related to quality control and assurance. If we are unable to obtain or maintain third-party manufacturing for product candidates, or to do so on commercially reasonable terms, we may not be able to develop and commercialize our product candidates successfully. Our or a third party’s failure to execute on our manufacturing requirements could adversely affect our business in a number of ways, including but not limited to:

If third parties on which we depend to conduct our preclinical and clinical studies do not perform as contractually required, fail to satisfy regulatory or legal requirements or miss expected deadlines, our development programs could be delayed with materially adverse effects on our business, financial condition, results of operations and prospects.

We rely on CROs and consultants to design, conduct, supervise and monitor preclinical studies for our product candidates and expect to rely on CROs, clinical data management organizations, institutions, and clinical investigators for the conduct of our future clinical trials. We and our CROs are required to comply with various regulations, including Good Laboratory Practices (GLP) and Good Clinical Practices (GCP) which are enforced by the FDA, and guidelines of the Competent Authorities of the Member States of the European Economic Area (EEA) and comparable foreign regulatory authorities to ensure that the health, safety and rights of patients are protected in clinical development, and that study data integrity is assured. Regulatory authorities ensure compliance with these requirements through periodic inspections of study sponsors, principal investigators and study sites. If we or any of our investigators or CROs fail to comply with applicable requirements, the data generated in our studies may be deemed unreliable and the FDA, the EMA or other comparable foreign regulatory authorities may require us to perform additional studies. We cannot be

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certain that upon inspection by a given regulatory authority, such regulatory authority will determine that any of our studies comply with such requirements.

Our CROs are not our employees, and except for remedies available to us under our agreements with such CROs, we cannot control whether or not they devote sufficient time and resources to our ongoing studies. If CROs do not successfully carry out their contractual duties or obligations or meet expected deadlines or if the quality or accuracy of the study data they obtain is compromised due to their failure to adhere to our protocols, regulatory requirements or for other reasons, our preclinical or clinical studies may be extended, delayed or terminated.

Because we have relied and continue to rely on third parties, our internal capacity to perform these functions is limited. Outsourcing these functions involves a risk that third parties may not perform to our standards, may not produce results in a timely manner or may fail to perform at all. In addition, the use of third-party service providers requires us to disclose our proprietary information to these parties, which could increase the risk that this information will be misappropriated. We currently have a relatively small number of employees, which limits the internal resources we have available to identify and monitor our third-party service providers. To the extent we are unable to identify and successfully manage the performance of third-party service providers in the future, our business may be adversely affected. Even though we carefully manage our relationships with our CROs, there can be no assurance that we will not be impacted by this type of challenges or delays in the future or that these delays or challenges will not have a material adverse impact on our business, financial condition and prospects.

If we cannot contract with acceptable third parties on commercially reasonable terms, or at all, or if these third parties do not carry out their contractual duties, satisfy legal and regulatory requirements for the conduct of preclinical or clinical studies or meet expected deadlines, our studies could be delayed and otherwise adversely affected. In all events, we are responsible for ensuring that each of our studies is conducted in accordance with the general investigational plan and protocols for the trial.

Our relationships with customers and third-party payors will be subject to applicable anti-kickback, fraud and abuse and other healthcare laws and regulations, which could expose us to criminal sanctions, civil penalties, contractual damages, reputational harm and diminished profits and future earnings.

Healthcare providers, physicians and third-party payors play a primary role in the recommendation and prescription of any product candidates for which we obtain marketing approval. Our future arrangements with third-party payors and customers may expose us to broadly applicable fraud and abuse and other healthcare laws and regulations that may constrain the business or financial arrangements and relationships through which we market, sell and distribute our products for which we obtain marketing approval. As a biopharmaceutical company, even though we do not and will not control referrals of healthcare services or bill directly to Medicare, Medicaid or other third-party payors, certain federal and state healthcare laws and regulations pertaining to fraud and abuse and patients’ rights are and will be applicable to our business. Restrictions under applicable federal and state healthcare laws and regulations that may affect our ability to operate include the following:

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The distribution of biopharmaceutical products is subject to additional requirements and regulations, including extensive record-keeping, licensing, storage and security requirements intended to prevent the unauthorized sale of biopharmaceutical products.

Comparable laws and regulations exist in the countries within the European Economic Area (EEA) and other countries where we may market our products in the future, including without limitation the United Kingdom, Canada and Brazil. Although in the EEA such laws are partially based upon European Union law, they may vary from country to country. Both healthcare and industry specific, as well as general EU and national laws, regulations and industry codes constrain, for example, our interactions with government officials and healthcare practitioners, and the handling of healthcare data. Non-compliance with any of these laws or regulations could lead to criminal or civil liability.

Efforts to ensure that our business arrangements with third parties will comply with applicable healthcare laws and regulations will involve substantial costs. It is possible that governmental authorities will conclude that our business practices may not comply with current or future statutes, regulations or case law involving applicable fraud and abuse or other healthcare laws and regulations. If our operations are found to be in violation of any of these laws or any other governmental regulations that may apply to us, we may be subject to significant civil, criminal and administrative penalties, damages, fines, disgorgement, imprisonment, reputational harm, exclusion from government funded healthcare programs, such as Medicare and Medicaid, and the curtailment or restructuring of our operations, as well as additional reporting obligations and oversight if we become subject to a corporate integrity agreement or other agreement to resolve allegations of non-compliance with these laws. If any physicians or other healthcare providers or entities with whom we expect to do business are found to not be in compliance with applicable laws, they may be subject to similar penalties. In addition, the approval and commercialization of any product candidate we develop outside the United States will also likely subject us to foreign equivalents of the healthcare laws mentioned above, among other foreign laws. All of these could harm our ability to operate our business and our financial results.

Our employees may engage in misconduct or other improper activities, including noncompliance with regulatory standards and requirements, which could have a material adverse effect on our business.

We are exposed to the risk of employee fraud or other misconduct. Misconduct by employees could include intentional failures to comply with FDA or EMA regulations or similar regulations of other foreign regulatory authorities, to provide accurate information to the FDA, the EMA or other foreign regulatory authorities, to comply with certain manufacturing standards, to comply with U.S. federal and state healthcare fraud and abuse laws and regulations and similar laws and regulations established and enforced by comparable foreign regulatory authorities, to report financial information or data accurately or to disclose unauthorized activities to us. In particular, sales, marketing and business arrangements in the healthcare industry are subject to extensive laws and regulations intended to prevent fraud, kickbacks, self-dealing and other abusive practices. These laws and regulations may restrict or prohibit a wide range of pricing, discounting, marketing and promotion, sales commission, customer incentive programs and other business arrangements. Employee misconduct could also involve the improper use of information obtained in the course of clinical trials, which could result in regulatory sanctions and serious harm to our reputation. We have adopted and implemented a Code of Business Conduct and Ethics, but it is not always possible to identify and deter employee misconduct, and the precautions we take to detect and prevent this activity, such as employee training on enforcement of the Code of Business Conduct and Ethics, may not be effective in controlling unknown or unmanaged risks or losses or in protecting us from governmental investigations or other actions or lawsuits stemming from a failure to be in compliance with such laws or regulations. If any such actions are instituted against us, and we are not successful in defending ourselves or asserting our rights, those actions and any imposition of significant fines or other sanctions could have a significant impact on our business and results of operations.

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Our collaboration partnerships with pharmaceutical companies are important to our business. If these companies do not successfully develop drugs pursuant to these agreements, our business could be adversely affected.

Under the amended and restated research and collaboration agreement which we entered into with Lilly in December 2022, Lilly has been granted certain exclusive and non-exclusive rights to ProQR’s Axiomer Platform IP to exploit compounds and develop and commercialize products based on this ProQR platform. Should Lilly decide not to pursue or be unable to pursue the further development and subsequent commercialization, we would not be able to receive milestone payments or royalty revenues associated with this partnership, which could have a substantial impact on our revenue.

We may not succeed in finding and entering into one or more strategic partnerships for our ophthalmology assets on the terms that are attractive to us or at all.

As part of our strategy to focus our efforts on developing our Axiomer platform, we intend to seek one or more third parties to collaborate with respect to the development of our ophthalmology assets, or otherwise sell or transfer such assets in order to generate near-term value. These strategic transactions may be structured in a variety of ways, including receipt of upfront payments, license fees, milestone payments and downstream royalties. However, there can be no assurance that we will be able to identify such a strategic partner or enter into such a transaction with them, or to otherwise sell or transfer our ophthalmology assets. If we fail to do so, we would not receive any such payments related to these assets or otherwise derive any near-term value from them. Even if we are successful in finding a partner for these assets, it is uncertain if such partner will be able to conduct clinical trials meeting its clinical endpoints, obtain regulatory approval and market access in relevant countries. If the partner does not succeed in commercializing the products, we would not receive net sales royalties on such product. Furthermore, if we do sell or transfer these assets, we could be held liable to repay certain grants that were received in the context of the development of sepofarsen and ultevursen.

Risks Related to Our Intellectual Property

We may become involved in legal proceedings with third parties that infringe our intellectual property rights, the outcome of which would be uncertain and could have a material adverse effect on the success of our business.

We may from time to time become involved in legal proceedings challenging our intellectual property rights, including with respect to Axiomer. For example, one or more third parties may seek to invalidate these intellectual property rights. Our success will depend in part on our ability to obtain, maintain and enforce patent protection for our inventions. We may not be able to successfully prosecute the patent applications. If patents are issued or granted, we may fail to maintain these patents due to oppositions and/or other post grant procedures initiated by third parties, we may determine not to pursue litigation against other companies that are infringing these patents, or we may pursue litigation in a variety of ways. For example, we currently are facing oppositions in Japan and Europe with respect to patents relating to our Axiomer platform. If we are unsuccessful in defending our patents against these oppositions, we could lose patent protection for Axiomer and product candidates developed thereunder in these jurisdictions. Further, intellectual property rights may not provide us with complete exclusivity in the respective fields, which would allow for third parties to develop competing products and technologies, which could adversely affect our business and harm our prospects.

We have licensed patent rights from third-party owners or licensees for our ophthalmology programs and if we fail to comply with our obligations in our intellectual property licenses, we could lose rights that are a prerequisite for partnering the ophthalmology assets.

We are party to licenses to third-party intellectual property for certain product candidates that we are seeking third party partners to continue their development. For Leber Congenital Amaurosis, we have a world-wide exclusive sublicensable and royalty-bearing license to patent rights owned by the Radboud University Medical Center (Radboud) and license to patent rights owned by Inserm Transfert (Inserm) for the commercial sale of antisense oligonucleotides that cause exon skipping in CEP290 pre-mRNA. For Usher, we have a world-wide exclusive sublicensable and royalty-bearing license to patent rights owned by Radboud, for the commercial sale of antisense oligonucleotides that cause exon skipping in USH2A pre-mRNA. For adRP, we have a world-wide exclusive license to patent rights owned by Ionis Pharmaceuticals, Inc. for the commercial use of gapmers that target mutated Rhodopsin (P23H) mRNA. For Fuchs Endothelial Corneal

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Dystrophy, we have a world-wide exclusive sublicensable and royalty-bearing license to patent rights owned by Vico Therapeutics B.V. for the prophylactic and therapeutic use of antisense oligonucleotides for the treatment of FECD.

Our licensing arrangements impose diligence, development, regulatory and commercialization milestones, and royalty, insurance and other obligations on us. If we fail to comply with these obligations, including with respect to programs that are part of the ophthalmology portfolio that we have suspended as part of the strategy update announced in August 2022, licensors may have the right to terminate these agreements, which may hamper our ability to find a strategic partner for these programs or may lead to other adverse consequences or payment obligations under the agreements. Such an occurrence could materially adversely affect the value of the product candidate being developed under any such agreement, which would in turn affect our ability to find a strategic partner.

Obtaining and maintaining our patent protection depends on compliance with various procedural, document submission, fee payment and other requirements imposed by governmental patent agencies, and our patent protection could be reduced or eliminated for non-compliance with these requirements.

Periodic maintenance fees on any issued patent are due to be paid to the United States Patent and Trademark Office (U.S. PTO) the European Patent Office (EPO) and other foreign patent agencies in several stages over the lifetime of the patent. The U.S. PTO, EPO and various foreign national or international patent agencies require compliance with a number of procedural, documentary, fee payment and other similar provisions during the patent application process. While an inadvertent lapse can in many cases be rectified by payment of a late fee or by other means in accordance with the applicable rules, there are situations in which noncompliance can result in abandonment or lapse of the patent or patent application, resulting in partial or complete loss of patent rights in the relevant jurisdiction. Non-compliance events that could result in abandonment or lapse of patent rights include, but are not limited to, failure to timely file national and regional stage patent applications based on our international patent application, failure to respond to official actions within prescribed time limits, non-payment of fees and failure to properly legalize and submit formal documents. If we or our licensors fail to maintain the patents and patent applications covering our product candidates, our competitors might be able to enter the market, which would have a material adverse effect on our business.

We or our licensors or any future collaborators or strategic partners may become subject to third party claims or litigation alleging infringement of patents or other proprietary rights or seeking to invalidate patents or other proprietary rights, and we may need to resort to litigation to protect or enforce our patents or other proprietary rights, all of which could be costly, time consuming, delay or prevent the development and commercialization of our product candidates, or put our patents and other proprietary rights at risk.

We or our licensors or any future collaborators or strategic partners may be subject to third-party claims for infringement or misappropriation of patent or other proprietary rights. We are generally obligated under our license or collaboration agreements to indemnify and hold harmless our licensors or collaborators for damages arising from intellectual property infringement by us. If we or our licensors, or any future collaborators or strategic partners, are found to infringe a third-party patent or other intellectual property rights, we could be required to pay damages, potentially including treble damages, if we are found to have willfully infringed. In addition, we or our licensors, or any future collaborators or strategic partners, may choose to seek, or be required to seek, a license from a third party, which may not be available on acceptable terms, if at all. Even if a license can be obtained on acceptable terms, the rights may be non-exclusive, which could give our competitors access to the same technology or intellectual property rights licensed to us. If we fail to obtain a required license, we or any future collaborator may be unable to effectively market product candidates based on our technology, which could limit our ability to generate revenue or achieve profitability and possibly prevent us from generating revenue sufficient to sustain our operations. In addition, we may find it necessary to pursue claims or initiate lawsuits to protect or enforce our patent or other intellectual property rights. The cost to us in defending or initiating any litigation or other proceeding relating to patent or other proprietary rights, even if resolved in our favor, could be substantial, and litigation would divert our management’s attention for a significant amount of time. Some of our competitors may be able to sustain the costs of complex patent litigation more effectively than we can because they have substantially greater resources. Uncertainties resulting from the initiation and continuation of patent litigation or other proceedings could delay our research and development efforts and limit our ability to continue our operations.

Further, if we were to initiate legal proceedings against a third party to enforce a patent covering one of our products or our technology, the defendant could counterclaim that our patent is invalid or unenforceable. In patent litigation in the

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U.S. and in most European countries, defendant counterclaims alleging invalidity or unenforceability are commonplace. Grounds for a validity challenge could be an alleged failure to meet any of several statutory requirements, for example, lack of novelty, obviousness or non-enablement. Grounds for an unenforceability assertion could be an allegation that someone connected with prosecution of the patent withheld relevant information from the U.S. PTO, or made a misleading statement, during prosecution. The outcome following legal assertions of invalidity and unenforceability during patent litigation is unpredictable. With respect to the validity question, for example, we cannot be certain that there is no invalidating prior art, of which we and the patent examiner were unaware during prosecution. If a defendant were to prevail on a legal assertion of invalidity or unenforceability, we would lose at least part, and perhaps all, of the patent protection on one or more of our products or certain aspects of our platforms’ technology. Such a loss of patent protection could have a material adverse impact on our business. Patents and other intellectual property rights also will not protect our technology if competitors design around our protected technology without legally infringing our patents or other intellectual property rights.

Third parties may initiate legal proceedings alleging that we are infringing their intellectual property rights, the outcome of which would be uncertain and could have a material adverse effect on the success of our business.

Our business depends upon our ability to develop, manufacture and, if approved, market and sell our product candidates, and to use our proprietary technologies without infringing the proprietary rights of third parties. We cannot guarantee that none of our product candidates, their manufacture, use, sale, offer for sale, or importation into the United States or into any country of the EEA will be held to infringe a third-party patent. As a result, we may become party to, or be threatened with, future adversarial proceedings or litigation regarding intellectual property rights with respect to our products and technology, including litigation in a Federal District court, or an interference or a post grant proceeding before the U.S. PTO or litigation in foreign courts or proceedings before foreign patent offices. Third parties may assert infringement claims against us based on existing patents or patents that may be granted in the future.

Furthermore, in the event a thus far unidentified third party were to assert an infringement claim against us and we were ultimately found to infringe the third party’s intellectual property rights, we could be required to obtain a license from such third party to continue developing and commercializing our products and technology. However, we may not be able to obtain an appropriate license on commercially reasonable terms or at all. Even if we are able to obtain a license, it may be non-exclusive, thereby giving our competitors access to the same technologies licensed to us. We could be forced, including by court order, to cease commercializing the infringing technology or product. In addition, in any such proceeding or litigation, we could be found liable for monetary damages. A finding of infringement could prevent us from commercializing our product candidates or force us to cease some of our business operations, which could materially harm our business. Any claims by third parties that we have misappropriated their confidential information or trade secrets could have a similar negative impact on our business.

If the third parties from whom we license patent rights do not properly or successfully obtain, maintain or enforce the patents underlying such licenses, or if they retain or license to others any competing rights, our competitive position and business prospects may be adversely affected.

Our success will further depend in part on the ability of our licensors to obtain, maintain and enforce patent protection for our licensed intellectual property, regardless of the exclusive or non-exclusive nature of these rights. Our licensors may not successfully prosecute the patent applications licensed to us. Even if patents are issued or granted, our licensors may fail to maintain these patents, may determine not to pursue litigation against other companies that are infringing these patents, or may pursue litigation less aggressively than we would. Further, the license agreements may not provide us with a complete freedom to operate in the respective fields, which would allow for third parties to develop competing products. Without protection for, or exclusive right to, the intellectual property we license, other companies might be able to offer substantially identical products for sale, which could adversely affect our competitive business position and harm our business prospects.

If we are not able to adequately prevent disclosure of trade secrets and other proprietary information, the value of our technology and products could be significantly diminished.

We rely on trade secrets to protect our proprietary technologies, especially where we do not believe patent protection is appropriate or obtainable. However, trade secrets are difficult to protect. We rely in part on confidentiality agreements

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with our employees, consultants, outside scientific collaborators, sponsored researchers, contract manufacturers, vendors and other advisors to protect our trade secrets and other proprietary information. These agreements may not effectively prevent disclosure of confidential information and may not provide an adequate remedy in the event of unauthorized disclosure of confidential information. In addition, we cannot guarantee that we have executed these agreements with each party that may have or has had access to our trade secrets.

Any party with whom we have executed a confidentiality agreement may breach that agreement and disclose our proprietary information, including our trade secrets, and we may not be able to obtain adequate remedies for such breaches. Enforcing a claim that a party illegally disclosed or misappropriated a trade secret is difficult, expensive and time-consuming, and the outcome is unpredictable. In addition, some courts inside and outside the United States are less willing or unwilling to protect trade secrets. If any of our trade secrets were to be lawfully obtained or independently developed by a competitor, we would have no right to prevent them, or those to whom they disclose such trade secrets, from using that technology or information to compete with us. If any of our trade secrets were to be disclosed to or independently developed by a competitor or other third-party, our competitive position could be harmed.

We may be subject to claims that we or our employees or consultants have wrongfully used or disclosed alleged trade secrets of our employees’ or consultants’ former employers or their clients. These claims may be costly to defend and if we do not successfully do so, we may be required to pay monetary damages and may lose valuable intellectual property rights or personnel.

Many of our employees were previously employed at universities or biotechnology or pharmaceutical companies, including our competitors or potential competitors. Although no claims against us are currently pending, we may be subject to claims in the future that these employees or we have inadvertently or otherwise used or disclosed trade secrets or other proprietary information of their former employers. Litigation may be necessary to defend against these claims. If we fail in defending such claims, in addition to paying monetary damages, we may lose valuable intellectual property rights or personnel. A loss of key research personnel or their work product could compromise our ability to commercialize, or prevent us from commercializing, our product candidates, which could severely harm our business. Even if we are successful in defending against these claims, litigation could result in substantial costs and be a distraction to management.

We may not be able to protect our intellectual property rights throughout the world.

Filing, prosecuting and defending patents on all of our product candidates throughout the world would be prohibitively expensive. Competitors may use our technologies in jurisdictions where we have not obtained patent protection to develop their own products and, further, may be able to export otherwise infringing products to territories where we have patent protection but where enforcement is not as strong as that in the United States. These products may compete with our products in jurisdictions where we do not have any issued patents and our patent claims or other intellectual property rights may not be effective or sufficient to prevent them from so competing.

Many companies have encountered significant problems in protecting and defending intellectual property rights in certain foreign jurisdictions. The legal systems of certain countries, particularly certain developing countries, do not favor the enforcement of patents and other intellectual property protection, particularly those relating to biopharmaceuticals, which could make it difficult for us to stop the infringement of our patents or marketing of competing products in violation of our proprietary rights generally. For example, the Special 301 Report (April 2022) from the Office of the United States Trade Representative identified a number of countries, including India and China, where challenges to the procurement and enforcement of patent rights have been reported. Several countries, including India and China, have been listed in the report every year since 1989. As a result, proceedings to enforce our patent rights in certain foreign jurisdictions could result in substantial cost and divert our efforts and attention from other aspects of our business.

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Risks Related to the Commercialization of Our Product Candidates

If any of our product candidates are approved for marketing and commercialization and we are unable to develop sales, marketing and distribution capabilities on our own or enter into agreements with third parties to perform these functions on acceptable terms, we will be unable to successfully commercialize any such future products.

Even if any of our product candidates are approved, we currently have no sales, marketing or distribution capabilities or experience. In addition, we intend to consider out-licensing, spinouts or collaborative partnerships to develop and commercialize our RNA technologies or programs. If any of our product candidates are approved, we will need to enter into collaborations with third parties to provide sales, marketing and distribution capabilities to commercialize such products or develop these capabilities internally, which would be expensive and time-consuming. If we decide to rely on third parties with such capabilities to market our products or decide to co-promote products with collaborators, we will need to establish and maintain marketing and distribution arrangements with such third parties, and there can be no assurance that we will be able to enter into such arrangements on acceptable terms or at all. In entering into third-party marketing or distribution arrangements, any revenue we receive will depend upon the efforts of the third parties and there can be no assurance that such third parties will have adequate sales and distribution capabilities for our products or be successful in gaining market acceptance of any approved product. If we decide to market our products directly, we would need to commit significant financial and managerial resources to develop a marketing and sales force with technical expertise and supporting distribution, administration and compliance capabilities. If we are not successful in commercializing any product approved in the future, either on our own or through third parties, our business, financial condition, results of operations and prospects could be materially adversely affected.

We face competition from entities that have developed or may develop product candidates for our target indications. If these companies develop technologies or product candidates more rapidly than we do or their technologies, including delivery technologies, are more effective, our ability to develop and successfully commercialize. whether on our own or with a collaborator, our product candidates may be adversely affected.

The development and commercialization of drugs is highly competitive. We compete with a variety of multinational pharmaceutical companies and specialized biotechnology companies, as well as technology being developed at universities and other research institutions. Our competitors have developed, are developing or may develop product candidates and processes competitive with our product candidates. Competitive therapeutic treatments include those that have already been approved and accepted by the medical community and any new treatments that may enter the market. We believe that a significant number of products are currently under development, and may become commercially available in the future, for the treatment of conditions for which we may try to develop product candidates. An overview of potential competitors is included in Item 4.B: “Business overview - Competition”.

Many of our competitors possess significantly greater financial, technical, manufacturing, marketing, sales and supply resources or experience than us. If we successfully obtain approval for any product candidate, we may face competition based on many different factors, including the safety and effectiveness of our products, the ease with which our products can be administered and the extent to which patients accept relatively new routes of administration, the timing and scope of regulatory approvals for these products, the availability and cost of manufacturing, marketing and sales capabilities, price, reimbursement coverage and patent position. Competing products could present superior treatment alternatives, including being more effective, safer, less expensive or marketed and sold more effectively than any products we may develop. Competitive products may make any products we develop obsolete or noncompetitive before we recover the expense of developing and commercializing our product candidates. Such competitors could also recruit our employees, which could negatively impact our level of expertise and our ability to execute our business plan. Furthermore, in our clinical studies we could be competing for the same patient population, resulting in a smaller population of suitable candidates and possibly delays and additional costs.

Even if we are able to commercialize any of our product candidates, whether on our own or with a collaborator, the products may not receive coverage and adequate reimbursement from third-party payors, which could harm our business.

The availability of reimbursement by governmental and private payors is essential for most patients to be able to afford expensive treatments. Sales of any of our product candidates, if approved, by us or a collaborator will depend

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substantially on the extent to which the costs of these product candidates will be paid by health maintenance, managed care, pharmacy benefit and similar healthcare management organizations, or reimbursed by government health administration authorities, private health coverage insurers and other third-party payors. If reimbursement is not available, or is available only to limited levels, we or our collaborators may not be able to successfully commercialize any product candidate. Even if coverage is provided, the approved reimbursement amount may not be high enough to allow us to establish or maintain pricing sufficient to realize a sufficient return on our investment.

There is significant uncertainty related to the insurance coverage and reimbursement of newly approved products. In the United States, the principal decisions about reimbursement for new medicines are typically made by the Centers for Medicare & Medicaid Services (CMS), an agency within the U.S. Department of Health and Human Services, as CMS decides whether and to what extent a new medicine will be covered and reimbursed under Medicare. Private payors tend to follow CMS to a substantial degree. It is difficult to predict what CMS will decide with respect to reimbursement for fundamentally novel products such as ours, as there is no body of established practices and precedents for these new products. Moreover, reimbursement agencies in Europe may be more conservative than CMS. For example, a number of cancer drugs have been approved for reimbursement in the United States and have not been approved for reimbursement in certain European countries. Factors payors consider in determining reimbursement are based on whether the product is: (i) a covered benefit under its health plan; (ii) safe, effective and medically necessary; (iii) appropriate for the specific patient; (iv) cost-effective; and (v) neither experimental nor investigational.

The intended use of a drug product by a physician can also affect pricing. For example, CMS could initiate a National Coverage Determination administrative procedure, by which the agency determines which uses of a therapeutic product would and would not be reimbursable under Medicare. This determination process can be lengthy, thereby creating a long period during which the future reimbursement for a particular product may be uncertain.

Outside the United States, particularly in Member States of the European Union, the pricing of prescription drugs is subject to governmental control. In these countries, pricing negotiations or the successful completion of health technology assessment procedures with governmental authorities can take considerable time after receipt of marketing approval for a product. In addition, there can be considerable pressure by governments and other stakeholders on prices and reimbursement levels, including as part of cost containment measures. Certain countries allow companies to fix their own prices for medicines, but monitor and control company profits. Political, economic and regulatory developments may further complicate pricing negotiations, and pricing negotiations may continue after reimbursement has been obtained. Reference pricing used by various European Union Member States and parallel distribution, or arbitrage between low-priced and high-priced Member States, can further reduce prices. In some countries, we or our collaborators may be required to conduct a clinical trial or other studies that compare the cost-effectiveness of our RNA technology candidates to other available therapies in order to obtain or maintain reimbursement or pricing approval. Publication of discounts by third-party payors or authorities may lead to further pressure on the prices or reimbursement levels within the country of publication and other countries. If reimbursement of any product candidate approved for marketing is unavailable or limited in scope or amount, or if pricing is set at unsatisfactory levels, our business, financial condition, results of operations or prospects could be adversely affected.

Moreover, efforts by governmental and other third-party payors, in the United States and abroad, to cap or reduce healthcare costs may cause such organizations to limit both coverage and level of reimbursement for new products approved and, as a result, they may not cover or provide adequate payment for our product candidates. We expect to experience pricing pressures in connection with the sale, whether by us or a collaborator, of any of our product candidates due to the trend toward managed healthcare, the increasing influence of health maintenance organizations and additional legislative changes. The downward pressure on healthcare costs in general, particularly prescription drugs and surgical procedures and other treatments, has become very intense. As a result, increasingly high barriers are being erected to the entry of new products.

Even if we receive marketing approval for any of our product candidates, they may not achieve broad market acceptance, which would limit the revenue that we generate from its sales.

The commercial success of any of our product candidates, if approved by the FDA, the EMA or other regulatory authorities, will depend upon the awareness and acceptance of the product among the medical community, including

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physicians, patients, patient advocacy groups and healthcare payors. Market acceptance of any of our product candidates, if approved, will depend on a number of factors, including, among others:

Recently enacted and future legislation, including potentially unfavorable pricing regulations or other healthcare reform initiatives, may increase the difficulty and cost for us to obtain marketing approval of, and commercialize, our product candidates and may negatively affect the prices we may obtain.

In the United States and some foreign jurisdictions, there have been, and continue to be, several legislative and regulatory changes and proposed changes regarding the healthcare system that could prevent or delay marketing approval of our product candidates, whether by us or a collaborator, restrict or regulate post-approval activities or affect our or a collaborator’s ability to profitably sell any product candidates for which we obtain marketing approval.

In the United States, the Medicare Prescription Drug, Improvement, and Modernization Act of 2003 (the Medicare Modernization Act) established the Medicare Part D program and provided authority for limiting the number of drugs that will be covered in any therapeutic class thereunder. The Medicare Modernization Act, including its cost reduction initiatives, could decrease the coverage and reimbursement rate that we or a collaborator receive for any of our approved products. Furthermore, private payors often follow Medicare coverage policies and payment limitations in setting their own reimbursement rates. Therefore, any reduction in reimbursement that results from the Medicare Modernization Act may result in a similar reduction in payments from private payors.

In March 2010, the Affordable Care Act (ACA) was enacted, which substantially changed the way health care is financed by both governmental and private insurers, and significantly impacted the U.S. biopharmaceutical industry. The ACA imposes a significant annual fee on companies that manufacture or import branded prescription drug products. It also contains substantial new provisions intended to broaden access to health insurance, reduce or constrain the growth of health care spending, enhance remedies against healthcare fraud and abuse, add new transparency requirements for the healthcare and health insurance industries, and impose additional health policy reforms, any of which could negatively impact our business. Among other things, it subjects biological products to potential competition by lower-cost biosimilars, expands the types of entities eligible for the 340B drug discount program, introduced a new methodology by which rebates owed by manufacturers under the Medicaid Drug Rebate Program are calculated for drugs that are inhaled, infused, instilled, implanted or injected; increased the minimum Medicaid rebates owed by manufacturers under the Medicaid Drug Rebate Program and extended the rebate program to individuals enrolled in

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Medicaid managed care organizations, established annual fees and taxes on manufacturers of certain branded prescription drugs, and created a new Medicare Part D coverage gap discount program, in which manufacturers must agree to offer 70% point-of-sale discounts off negotiated prices of applicable brand drugs to eligible beneficiaries during their coverage gap period, as a condition for the manufacturer’s outpatient drugs to be covered under Medicare Part D. The ACA is likely to continue the downward pressure on pharmaceutical and medical device pricing, especially under the Medicare program, and may also increase our regulatory burdens and operating costs.

Since its enactment, there have been numerous judicial, administrative, executive, and legislative challenges to certain aspects of the ACA. On June 17, 2021, the U.S. Supreme Court dismissed the most recent judicial challenge to the ACA brought by several states without specifically ruling on the constitutionality of the ACA. Prior to the Supreme Court's decision, President Biden issued an Executive Order to initiate a special enrollment period from February 15, 2021 through August 15, 2021 for purposes of obtaining health insurance coverage through the ACA marketplace. The Executive Order also instructed certain governmental agencies to review and reconsider their existing policies and rules that limit access to healthcare, including among others, reexamining Medicaid demonstration projects and waiver programs that include work requirements, and policies that create unnecessary barriers to obtaining access to health insurance coverage through Medicaid or the ACA. It is unclear how other healthcare reform measures of the Biden administrations or other efforts, if any, to challenge repeal or replace the ACA, will impact our business.

In addition, other legislative and regulatory changes have been proposed and adopted in the United States since the ACA was enacted. For example:

Additionally, there has been increasing legislative and enforcement interest in the United States with respect to drug pricing practices. There has been heightened governmental scrutiny over the manner in which manufacturers set prices for their marketed products, which has resulted in several U.S. Congressional inquiries and proposed and enacted federal and state legislation designed to, among other things, bring more transparency to drug pricing, reduce the cost of prescription drugs under Medicare, and review the relationship between pricing and manufacturer patient programs.

Although a number of these and other proposed measures may require authorization through additional legislation to become effective, and both the Biden administration and Congress have indicated that they will continue to seek new legislative and/or administrative measures to control drug costs.

For example, the Inflation Reduction Act of 2022, or IRA includes several provisions that will impact our business to varying degrees, including provisions that reduce the out-of-pocket cap for Medicare Part D beneficiaries to $2,000 starting in 2025; impose new manufacturer financial liability on certain drugs in Medicare Part D, allow the U.S. government to negotiate Medicare Part B and Part D price caps for certain high-cost drugs and biologics without generic or biosimilar competition, require companies to pay rebates to Medicare for certain drug prices that increase faster than inflation, and delay the rebate rule that would limit the fees that pharmacy benefit managers can charge.

We expect that these and other healthcare reform measures that may be adopted in the future, may result in more rigorous coverage criteria and in additional downward pressure on the price that we, or our collaborators, would receive for any approved drug, which could have an adverse effect on customers for our product candidates. Any reduction in reimbursement from Medicare or other government programs may result in a similar reduction in payments from private payors.

Further, legislative and regulatory proposals have been made to expand post-approval requirements and restrict sales and promotional activities for pharmaceutical products. We cannot be sure whether additional legislative changes will be enacted, or whether FDA regulations, guidance or interpretations will be changed, or what the impact of such changes on the marketing approvals, if any, of our product candidates, may be. In addition, increased scrutiny by the U.S. Congress

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of the FDA’s approval process may significantly delay or prevent marketing approval, as well as subject us to more stringent product labeling and post-marketing conditions and other requirements.

Individual states in the U.S. have also become increasingly aggressive in passing legislation and implementing regulations designed to control pharmaceutical and biological product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing. Legally mandated price controls on payment amounts by third-party payors or other restrictions could harm our business, results of operations, financial condition and prospects. In addition, regional healthcare authorities and individual hospitals are increasingly using bidding procedures to determine what pharmaceutical products and which suppliers will be included in their prescription drug and other healthcare programs. This could reduce the ultimate demand for our products or put pressure on our product pricing, which could negatively affect our business, results of operations, financial condition and prospects.

In the European Union, similar political, economic and regulatory developments may affect our, or our collaborators’, ability to profitably commercialize our current or any future products. In addition to continuing pressure on prices and cost containment measures, legislative developments at the European Union or Member State level may result in significant additional requirements or obstacles that may increase our operating costs. The delivery of healthcare in the European Union, including the establishment and operation of health services and the pricing and reimbursement of medicines, is almost exclusively a matter for national, rather than European Union, law and policy. National governments and health service providers have different priorities and approaches to the delivery of health care and the pricing and reimbursement of products in that context. In general, however, the healthcare budgetary constraints in most European Union Member States have resulted in restrictions on the pricing and reimbursement of medicines by relevant health service providers. Coupled with ever-increasing European Union and national regulatory burdens on those wishing to develop and market products, this could prevent or delay marketing approval of our product candidates, restrict or regulate post-approval activities and affect our, or our collaborators’, ability to commercialize any products for which we obtain marketing approval. In international markets, reimbursement and healthcare payment systems vary significantly by country, and many countries have instituted price ceilings on specific products and therapies.

There have been, and likely will continue to be, legislative and regulatory proposals at the foreign, federal and state levels directed at broadening the availability of healthcare and containing or lowering the cost of healthcare. We cannot predict the likelihood, nature or extent of government regulation that may arise from future legislation or administrative action, either in the U.S. or abroad. The implementation of cost containment measures or other healthcare reforms may prevent us from being able to generate revenue, attain profitability, or commercialize our products. Such reforms could have an adverse effect on anticipated revenue from product candidates that we may successfully develop and for which we may obtain regulatory approval and may affect our overall financial condition and ability to develop product candidates.

Even if any of our product candidates receive regulatory approval, they may still face future development and regulatory difficulties and we will be subject to extensive post-approval regulatory requirements and review.

If we obtain regulatory approval for any of our product candidates, we and any approved product candidates would be subject to extensive ongoing requirements and review by the FDA, the EMA and foreign regulatory authorities governing the manufacture, quality control, further development, labeling, packaging, storage, distribution, safety surveillance, import, export, advertising, promotion, recordkeeping and reporting of safety and other post-market information. The safety profile of any product will continue to be closely monitored by the FDA, the EMA and comparable foreign regulatory authorities after approval. If the FDA, the EMA or comparable foreign regulatory authorities become aware of new safety information after approval of any of our product candidates, these regulatory authorities may require labeling changes or establishment of a risk management strategy, impose significant restrictions on a product’s indicated uses or marketing, impose ongoing requirements for potentially costly post-approval studies or post-market surveillance or impose a recall.

In addition, manufacturers of therapeutic products and their facilities are subject to continual review and periodic inspections by the FDA, the EMA and other regulatory authorities for compliance with cGMP regulations. For certain commercial prescription drug products, manufacturers and other parties involved in the supply chain must also meet

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chain of distribution requirements and build electronic, interoperable systems for product tracking and tracing and for notifying the FDA of counterfeit, diverted, stolen and intentionally adulterated products or other products that are otherwise unfit for distribution in the United States. If we or a regulatory agency discover previously unknown problems with a product, such as adverse events of unanticipated severity or frequency, or problems with the facility where the product is manufactured, a regulatory agency may impose restrictions on that product, the manufacturing facility or us, including requiring recall or withdrawal of the product from the market or suspension of manufacturing. If we, our product candidates or the manufacturing facilities for our product candidates fail to comply with applicable regulatory requirements, a regulatory agency may, among other things:

The occurrence of any event or penalty described above may inhibit our ability to commercialize our products or generate revenue.

We are subject to anti-corruption laws, as well as export control laws, customs laws, sanctions laws and other laws governing our operations. If we fail to comply with these laws, we could be subject to civil or criminal penalties, other remedial measures and legal expenses, which could adversely affect our business, results of operations and financial condition.

Our operations are subject to anti-corruption laws, including the U.K. Bribery Act 2010 (Bribery Act), the U.S. Foreign Corrupt Practices Act (FCPA) and other anti-corruption laws that apply in countries where we do business and may do business in the future. The Bribery Act, the FCPA and other similar laws generally prohibit us, our officers, and our employees and intermediaries from bribing, being bribed or making other prohibited payments to government officials or other persons to obtain or retain business or gain some other business advantage. If we were to pursue sales, marketing or distribution activities in the future, we may operate in a number of jurisdictions that pose a high risk of potential Bribery Act or FCPA violations, and we may participate in collaborations and relationships with third parties whose actions could potentially subject us to liability under the Bribery Act, the FCPA or local anti-corruption laws. In addition, we cannot predict the nature, scope or effect of future regulatory requirements to which our international operations might be subject or the manner in which existing laws might be administered or interpreted.

We are also subject to other laws and regulations governing our international operations, including regulations administered by the governments of the United Kingdom and the United States, and authorities in the European Union, including applicable export control regulations, economic sanctions on countries and persons, customs requirements and currency exchange regulations, collectively referred to as the Trade Control laws, and anti-money laundering laws.

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There is no assurance that we will be completely effective in ensuring our compliance with all applicable anti-corruption laws, including the Bribery Act, the FCPA or other legal requirements, including Trade Control laws. If we are not in compliance with the Bribery Act, the FCPA, other anti-corruption laws, Trade Control laws or anti-money laundering laws, we may be subject to criminal and civil penalties, disgorgement and other sanctions and remedial measures, and legal expenses, which could have an adverse impact on our business, financial condition, results of operations and liquidity. Likewise, any investigation of any potential violations of the Bribery Act, the FCPA, other anti-corruption laws, Trade Control laws or anti-money laundering laws by U.K., U.S. or other authorities could also have an adverse impact on our reputation, our business, results of operations and financial condition.

If we receive regulatory approvals and were to pursue sale, marketing or distribution activities ourselves, we may market our product candidates in multiple jurisdictions where we have limited or no operating experience and may be subject to increased business and economic risks that could affect our financial results.

If we receive regulatory approvals, we may market our product candidates ourselves in jurisdictions where we have limited or no experience in marketing, developing and distributing our products. Certain markets have substantial legal and regulatory complexities that we may not have experience navigating. We would be subject to a variety of risks inherent in doing business internationally, including:

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The FDA, the EMA and other regulatory agencies actively enforce the laws and regulations prohibiting the promotion of off-label uses. If we are found to have improperly promoted off-label uses, we may become subject to significant liability.

The FDA, the EMA and other regulatory agencies strictly regulate the promotional claims that may be made about prescription products if approved. In particular, a product may not be promoted for uses that are not approved by the FDA, the EMA or other similar regulatory agencies as reflected in the product’s approved labeling. If we receive marketing approval for our product candidates, physicians may nevertheless prescribe them to their patients in a manner that is inconsistent with the approved label. If we are found to have promoted such off-label uses, we may become subject to significant liability.

In the United States, engaging in impermissible promotion of our products for off-label uses can also subject us to false claims litigation under federal and state statutes, which can lead to civil and criminal penalties and fines and agreements that materially restrict the manner in which we promote or distribute those products. These false claims statutes include the federal False Claims Act, which allows any individual to bring a lawsuit against a pharmaceutical or medical device company on behalf of the federal government alleging submission of false or fraudulent claims, or causing to present such false or fraudulent claims, for payment by a federal program such as Medicare or Medicaid. If the government prevails in the lawsuit, the individual will share in any fines or settlement funds. Since 2004, these False Claims Act lawsuits against pharmaceutical and medical device companies have increased significantly in volume and breadth, leading to several substantial civil and criminal settlements based on certain sales practices promoting off-label drug uses. This growth in litigation has increased the risk that a company will have to defend a false claim action, pay settlement fines or restitution, agree to comply with burdensome reporting and compliance obligations, and be excluded from the Medicare, Medicaid, and other federal and state healthcare programs. If we do not lawfully promote our approved products, we may become subject to such litigation and, if we are not successful in defending against such actions, those actions may have a material adverse effect on our business, financial condition and results of operations.

Adverse decisions of tax authorities or changes in tax treaties, laws, rules or interpretations could have a material adverse effect on our business, results of operations, financial condition and cash flows.

The tax laws and regulations in the Netherlands, the jurisdiction of our incorporation and our current resident state for tax purposes, may be subject to change and there may be changes in enforcement of tax law. Additionally, European and other tax laws and regulations are complex and subject to varying interpretations. We cannot be sure that our interpretations are accurate or that the responsible tax authority agrees with our views. If our tax positions are challenged by the tax authorities, we could incur additional tax liabilities, which could increase our costs of operations and have a material adverse effect on our business, financial condition, and results of operations.

Further changes in the tax laws of the jurisdictions in which we operate could arise as a result of the base erosion and profit shifting (BEPS) project being undertaken by the Organisation for Economic Co-operation and Development (OECD). The OECD, which represents a coalition of member countries that encompass certain of the jurisdictions in which we operate or in which we could choose to set up operations in the future, is undertaking studies and publishing action plans that include recommendations aimed at addressing what they believe are issues within tax systems that may lead to tax avoidance by companies. It is possible that the jurisdictions in which we do business could react to the BEPS initiative or their own concerns by enacting tax legislation that could adversely affect us or our shareholders through increasing our tax liabilities.

Risks Related to Our Organization, Structure and Operations

Members of our management board and supervisory board and our principal shareholders and their affiliates have significant control over our company, which will limit other stakeholders’ ability to influence corporate matters and could delay or prevent a change in corporate control.

The holdings of the members of our management board and supervisory board and our principal shareholders and their affiliates, represent significant ownership, in the aggregate, of our outstanding ordinary shares (as set out in “Item 7.A.

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Major Shareholders”). As a result, these shareholders, if they act together, will be able to influence our management and affairs and control the outcome of matters submitted to our shareholders for approval, including the election of members of our management board and supervisory board and any sale, merger, consolidation, or sale of all or substantially all of our assets. These shareholders may have interests, with respect to their ordinary shares, which are different from other investors and the concentration of voting power among these shareholders may have an adverse effect on the price of our ordinary shares. In addition, this concentration of ownership might adversely affect the market price of our ordinary shares by:

Please see “Item 7.A. Major Shareholders” for more information regarding the ownership of our outstanding ordinary shares by our management board and supervisory board and our principal shareholders and their affiliates.

Any inability to attract and retain qualified key management and technical personnel would impair our ability to implement our business plan.

Our success largely depends on the continued service of key management and other specialized personnel. The loss of one or more members of our management board or other key employees or advisors could delay our research and development programs and materially harm our business, financial condition, results of operations and prospects. The relationships that our key managers have cultivated within our industry make us particularly dependent upon their continued employment with us. Moreover, we are dependent on the continued service of our technical personnel because of the highly technical nature of our product candidates and technologies and the specialized nature of the regulatory approval process. Because our management board and key employees are not obligated to provide us with continued service, they could terminate their employment or services with us at any time without penalty, subject to providing any required advance notice. Our future success will depend in large part on our continued ability to attract and retain other highly qualified scientific, technical and management personnel, as well as personnel with expertise in clinical testing, manufacturing, governmental regulation and commercialization. It is noteworthy that for 2023, given the increased and exclusive focus on the RNA editing technology platform, an ambitious hiring plan is put in place, which puts a higher risk factor on our ability to attract personnel. We face competition for personnel from other companies, universities, public and private research institutions, government entities and other organizations.

We will need to maintain a good relationship with our employees to maintain our operations. A deterioration in our relationships with our employees could have an adverse impact on our business.

In April and August 2022 , we announced an update on our company’s strategy that included a reduction in force totaling approximately 50% of our workforce. Our decision to engage in this reduction resulted from an assessment of our internal resources needs in light of our updated business strategy. This reduction represented a cost-cutting measure across the organization designed to extend our cash runway and to focus our development efforts exclusively on our RNA editing technology platform. These actions, concluded in March 2023, have caused substantial uncertainty as to job security for the rest of our employees and could damage employee morale across our organization, harm our recruiting and retention efforts and may distract the attention of our company and management from executing on our business strategy. Maintaining good relationships with our employees and operating effectively and efficiently across our organization are crucial to our operations and our success. If we are unable to successfully maintain such relationships or manage the uncertainty as a result of the reduction in the number of our residual workforce, and the complexity of operations, our business may be adversely affected.

We may experience difficulties in managing our growth and expanding our operations.

We have limited experience in drug development. As our product candidates enter and advance through preclinical studies, we will need to expand our development, regulatory and manufacturing capabilities or contract with other

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organizations to provide these capabilities for us. In the future, we expect to have to manage additional relationships with collaborators or partners, suppliers and other organizations. Our ability to manage our operations and future growth will require us to continue to improve our operational, financial and management controls, reporting systems and procedures. We may not be able to implement improvements to our management information and control systems in an efficient or timely manner and may discover deficiencies in existing systems and controls.

Data collection and use in the European Union and United Kingdom is governed by restrictive regulations governing the use, processing, and cross-border transfer of personal information.

We are subject to a number of laws and regulations relating to privacy and data protection, including, in relation to the European Union, the General Data Protection Regulation (EU) 2016/679 (the “EU GDPR”). Following the withdrawal of the United Kingdom from the European Union (“Brexit”), the EU GDPR has been incorporated into United Kingdom’s laws (“UK GDPR”). As the regulatory focus on privacy issues continues to increase and worldwide laws and regulations concerning the handling of personal data expand and become more complex (including in relation to privacy, the use of AI, the operation of digital platforms, and provision of digital services), we expect that potential risks related to data collection and use within the business may intensify. In addition, new laws or regulations governing privacy, security, the use of AI, the provision of digital services, and data protection may be introduced which could apply in future. The nature and extent of such additions and changes in data protection laws or regulations, and the application to, or impact they may have on, the Company, is uncertain.

The data protection laws applicable to us impact our ability to collect, augment, analyze, use, transfer and share personal data. For example, the EU GDPR and UK GDPR, among other obligations and requirements: (i) impose requirements relating to how an organization can collect and rely upon consent obtained from an individual to process their personal data; (ii) impose obligations in relation to the provision of information to individuals relating to the processing of their personal data; (iii) require organizations to notify personal data breaches to competent data protection authorities and/or individuals; and (iv) impose additional requirements in relation to the processing of certain categories of data (i.e. “sensitive information” or special category data), which includes health data, data revealing racial or ethnic origin, and genetic data. The EU GDPR and UK GDPR also grant individuals certain rights, subject to certain limitations, including the rights to request and access a copy of the personal data processed by an organization, to have inaccurate personal data rectified or completed if incomplete, to object to or restrict the processing of their personal data, and to request deletion of personal data.

Regulators can impose significant monetary fines for violations of laws and regulations relating to privacy and data protection. For example, non-compliance with certain obligations under the EU GDPR and UK GDPR may result in monetary penalties of up to, the greater of, 4 per cent. of the Company’ s worldwide turnover in the preceding financial year, or €20 million (under EU GDPR) or £17.5 million (under UK GDPR) as applicable, whichever is higher. The EU GDPR and UK GDPR, and other changes in laws or regulations associated with the enhanced protection of personal data, mean that the size of potential fines related to data protection and our costs of providing products and services, could result in changes to our business practices, and could prevent us from offering certain services in jurisdictions in which we operate. Although we have implemented contracts, policies and procedures designed to ensure compliance with applicable laws and regulations, there can be no assurance that our employees, contractors, partners, service providers or agents will not violate such laws and regulations or our contracts, policies and procedures. Additionally, public perception and standards related to the privacy of personal data can shift rapidly, in ways that may affect our reputation, the regulators’ approaches to enforcement of existing laws, or influence regulators to enact regulations and laws that may limit our ability to handle personal data or provide certain products and services.

The EU GDPR and UK GDPR, and other applicable data protection laws, also impose restrictions in relation to the international transfer of personal data. For example, in order to transfer data outside of the European Economic Area or the United Kingdom to a non-adequate country, the EU GDPR and UK GDPR (as applicable) requires us to enter into an appropriate transfer mechanism, and may require us to take additional steps to ensure an essentially equivalent level of data protection. These transfer mechanisms are subject to change, and implementing new or revised transfer mechanisms or ensuring an essentially equivalent protection may involve additional expense and potentially increased compliance risk. In the event a legislator, government, regulator or court imposes additional restrictions on international transfers, there may be operational interruption in the performance of services for customers and internal processing of employee

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information. Such restrictions may also increase our obligations in relation to carrying out international transfers of personal data, and incur additional expense and increased regulatory liabilities.

Despite Brexit, the EU and UK GDPR remain largely aligned. Currently, the most impactful point of divergence between the EU GDPR and the UK GDPR relates to these transfer mechanisms as explained above. There may be further divergence in the future, including with regard to administrative burdens. The United Kingdom has announced plans to reform the country’s data protection legal framework in its Data Reform Bill, which will introduce significant changes from the EU GDPR. This may lead to additional compliance costs and could increase our overall risk exposure as we may no longer be able to take a unified approach across the European Union and the United Kingdom, and we will need to amend our processes and procedures to align with the new framework.

Our failure to comply with U.S. data protection laws and regulations could lead to government enforcement actions and significant penalties against us, and adversely impact our operating results.

There are numerous laws and legislative and regulatory initiatives at the U.S. federal and state levels as well addressing privacy and security concerns, and some state privacy laws apply more broadly than HIPAA and associated regulations. For example, California enacted the California Consumer Privacy Act (CCPA), which creates new individual privacy rights for California consumers (as defined in the law) and places increased privacy and security obligations on entities handling personal information about residents of California. The CCPA requires covered companies to provide certain disclosures to consumers about its data collection, use and sharing practices, and to provide affected California residents with ways to opt-out of certain sales or transfers of personal information. The CCPA went into effect on January 1, 2020, and became enforceable by the California Attorney General on July 1, 2020. The CCPA provides for civil penalties for violations, as well as a private right of action for certain data breaches that result in the loss of personal information. This private right of action may increase the likelihood of, and risks associated with, data breach litigation. While there is currently an exception for protected health information that is subject to the Health Insurance Portability and Accountability Act of 1996, or HIPAA, and clinical trial regulations, as currently written, the CCPA may impact our business activities. There continues to be uncertainty surrounding the enforcement and implementation of the CCPA, exemplifying the vulnerability of our business to the evolving regulatory environment related to personal data and protected health information.

Additionally, a California ballot initiative, the California Privacy Rights Act (CPRA) was passed in November 2020 and became effective on January 1, 2023. The CPRA imposes additional obligations on companies covered by the legislation and significantly modifies the CCPA, including by expanding consumers’ rights with respect to certain sensitive personal information. The CPRA also creates a new state agency that is vested with authority to implement and enforce the CCPA, as modified by the CPRA. The effects of the CCPA, as modified by the CPRA are potentially significant and may require us to modify our data collection or processing practices and policies and to incur substantial costs and expenses in an effort to comply and increase our potential exposure to regulatory enforcement and/or litigation.

Certain other state laws impose similar privacy obligations and we anticipate that more states may enact legislation similar to the CCPA. Already, similar laws have been passed in Virginia, Utah, Colorado and Connecticut. The CCPA has prompted a number of proposals for new federal and state-level privacy legislation. Such proposed legislation, if enacted, may add additional complexity, variation in requirements, restrictions and potential legal risk, require additional investment of resources in compliance programs, impact strategies and the availability of previously useful data and could result in increased compliance costs and/or changes in business practices and policies.

We are increasingly dependent on information technology systems, and our systems and infrastructure face certain risks, including from cyber security breaches and data leakage, which in turn could lead to a determination that we have failed to comply with EU GDPR and UK GDPR, resulting in a fine or regulatory enforcement action.

We increasingly rely upon technology systems and infrastructure, including support provided by our partners and third parties, to support our business. For example, we routinely rely on our technology systems and infrastructure to aid us in the collection, use, storage and transfer, disclosure and other processing of voluminous amounts of data (including confidential, business, personal and other sensitive information). We also rely on systems for manufacturing, regulatory compliance and various other matters.

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The increasing use and evolution of technology, including cloud-based computing, and reliance on third parties creates additional opportunities for the unintentional, intentional and/or unauthorized exposure, dissemination and/or destruction of confidential information stored in our technology systems, infrastructure and products. Our computer systems, servers and other technology systems (and those of third parties that we use) are vulnerable to breakdown, interruption, cyber and other security attacks, system malfunction, unauthorized access and other events. Security threats, including cyber and other attacks are becoming increasingly sophisticated, frequent, and adaptive. For example, we have experienced an incident in which personnel information was inadvertently made available to company employees broadly. In response, we made the required reports to regulatory authorities and took remedial measures to secure such information systems from unauthorized and unintentional access. Any such vulnerability could compromise our technology systems and infrastructure and could expose personal and/or proprietary information (including sensitive personal information) to unauthorized third parties and/or cause permanent loss of such data. While we have invested in the protection of data and information technology, there can be no assurance that our efforts will prevent breakdowns, breaches in our systems or other incidents or ensure compliance with all applicable security and privacy laws, regulations and standards. We could also suffer strained relationships, increased costs (for security measures, remediation or otherwise), litigation (including class actions and stockholder derivative actions) or other negative consequences (including a decline in stock price) from breaches, cyber and other security attacks, industrial espionage, ransomware, email or phishing scams, malware or other cyber incidents, which may compromise our system infrastructure or lead to data leakage, either internally or at our third-party providers or other business partners.

Some cyber security incidents may be very difficult to prevent. For example, supply chain incidents involving previously unknown vulnerabilities in widely-used software are becoming increasingly common, of which the recent Log4j incidents are examples. While we are not currently aware of any impact from supply chain vulnerabilities including but not necessarily limited to Log4j, these are recent events, and the full scope of the attacks are not yet known. Therefore, there is residual risk that we may experience a security breach arising from the Log4j and other supply chain vulnerabilities.

While we have invested in the protection of data and information technology and in related training, there can be no assurance that our efforts will prevent significant breakdowns, attacks, breaches in our systems or other cyber incidents or ensure compliance with all applicable security and privacy laws, regulations and standards, including with respect to third-party service providers that utilize sensitive personal information, including protected health information on our behalf.

Our internal computer systems, or those of our CROs or other contractors or consultants, may fail or suffer security breaches, which could result in a material disruption of our product development programs, a determination that we have failed to comply with EU GDPR and UK GDPR, resulting in a fine, and adversely affect our business.

Despite the implementation of security measures, our information technology and other internal infrastructure systems and those of our CROs and other contractors and consultants are vulnerable to damage from computer viruses, cyberattacks and unauthorized access, natural disasters, terrorism, war and telecommunication and electrical failures. A significant disruption in the availability of our information technology and other internal infrastructure systems could cause interruptions in our collaborations with our partners and delays in our research and development work. For instance, the loss of preclinical or clinical data involving our product candidates could result in delays in our development and regulatory filing efforts and significantly increase our costs. To the extent that any disruption or security breach were to result in unauthorized disclosure of, or access to, or accidental or unlawful loss, destruction, alteration of, or damage to, our data, or inappropriate disclosure of confidential or proprietary information, we could incur liability, including fines for failure to comply with EU GDPR or UK GDPR as applicable (to the extent the data contained personal data), and the development of our product candidates could be delayed.

Our current operations are mainly concentrated in one location, and any events affecting this location may have material adverse consequences.

Our current operations are primarily located in our facilities in Leiden, the Netherlands. Any unplanned event, such as flood, fire, explosion, earthquake, extreme weather condition, medical epidemics, power shortage, telecommunication failure or other natural or manmade accidents or incidents that result in us being unable to fully utilize the facilities may have a material adverse effect on our ability to operate our business, particularly on a daily basis, and have significant

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negative consequences on our financial and operating conditions. Loss of access to these facilities may result in increased costs, delays in the development of our product candidates or interruption of our business operations. As part of our risk management policy, we maintain insurance coverage at levels that we believe are appropriate for our business. However, in the event of an accident or incident at these facilities, we cannot assure you that the amounts of insurance will be sufficient to satisfy any damages and losses. If our facilities are unable to operate because of an accident or incident or for any other reason, even for a short period of time, any or all of our research and development programs may be harmed.

Our international operations subject us to various operational risks, and our failure to manage these risks could adversely affect our results of operations.

We face significant operational risks as a result of doing business internationally, such as:

Inadequate funding for the FDA and other government agencies could hinder their ability to hire and retain key leadership and other personnel, which in turn could prevent new products from being developed or commercialized in a timely manner or otherwise prevent those agencies from performing normal business functions on which the operation of our business may rely, which could negatively impact our business.

The ability of the FDA to review and approve new products can be affected by a variety of factors, including government budget and funding levels, ability to hire and retain key personnel and accept the payment of user fees, and statutory, regulatory, and policy changes. Average review times at the agency have fluctuated in recent years as a result. In addition, government funding of other agencies on which our operations may rely, including those that fund research and development activities, is subject to the political process, which is inherently fluid and unpredictable.

Disruptions at the FDA and other agencies may also slow the time necessary for new drugs to be reviewed and/or approved by necessary government agencies, which would adversely affect our business. For example, over the last several years the U.S. government has shut down several times and certain regulatory agencies, such as the FDA, have had to furlough critical FDA and other government employees and stop critical activities. If a prolonged government shutdown occurs, it could significantly impact the ability of the FDA to timely review and process our regulatory submissions, which could have a material adverse effect on our business. Further, future shutdowns of other government

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agencies, such as the SEC, may also impact our business by delaying review of our public filings, which in turn could delay or frustrate our ability to access the public capital markets. Similar developments at regulators (including the EMA) in other countries could have similar impacts on our applications for marketing approval and on our business.

The investment of our cash and cash equivalents is subject to risks which may cause losses and affect the liquidity of these investments.

As at December 31, 2022 we had € 94,775,000 in cash and cash equivalents. To date, our cash and cash equivalents have been deposited primarily in savings and deposit accounts with original maturities of twelve months or less. Savings and deposit accounts generate small amounts of interest income, if any. In 2020, 2021, and 2022, some of our euro savings accounts required us to incur small amounts of interest expenses. Any future investments may include term deposits, corporate bonds, money market funds and government securities, all in accordance with our cash management policy. These investments are subject to general credit, liquidity, market and interest rate risks. For example, interest rates may be negative in the European Union. We may realize losses in the fair value of these investments or a complete loss of these investments, which would have a negative effect on our financial statements.

In addition, should our investments cease paying or reduce the amount of interest paid to us, our interest income would suffer. The materialization of any of the market risks associated with our investment portfolio may have an adverse effect on our results of operations, liquidity and financial condition.

We may be exposed to significant foreign exchange risk.

We incur portions of our expenses, and may in the future derive revenues, in currencies other than our functional currency (i.e. the euro), in particular, the U.S. dollar. As a result, we are exposed to foreign currency exchange risk as our results of operations and cash flows are subject to fluctuations in foreign currency exchange rates. We currently do not engage in hedging transactions to protect against uncertainty in future exchange rates between particular foreign currencies and the euro. Therefore, for example, an increase in the value of the U.S. dollar against the euro could be expected to have a negative impact on our expenditures, although it is our policy to match the currency of our cash and cash equivalents with expected cash out flows as much as practically feasible. We cannot predict the impact of foreign currency fluctuations, and foreign currency fluctuations in the future may adversely affect our financial condition, results of operations and cash flows.

Our business entails a significant risk of product liability and our ability to obtain sufficient insurance coverage could have a material effect on our business, financial condition, results of operations or prospects.

The use of our product candidates in preclinical studies, in clinical trials and the sale of any of our product candidates if approved, exposes us to the risk of product liability claims. Product liability claims might be brought against us by patients, healthcare providers or others selling or otherwise coming into contact with our product candidates. For example, we may be sued if any product we develop allegedly causes injury or is found to be otherwise unsuitable during product testing, manufacturing, marketing or sale. Any such product liability claims may include allegations of defects in manufacturing, defects in design, a failure to warn of dangers inherent in the product, including as a result of interactions with alcohol or other drugs, negligence, strict liability, and a breach of warranties. Claims could also be asserted under state consumer protection acts. If we become subject to product liability claims and cannot successfully defend ourselves against them, we could incur substantial liabilities. In addition, regardless of merit or eventual outcome, product liability claims may result in, among other things:

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We will need to maintain product liability insurance coverage for our clinical trials. We may not be able to obtain such coverage at a reasonable cost or in sufficient amounts to protect us against losses, including if insurance coverage becomes increasingly expensive. Large judgments have been awarded in class action lawsuits based on drugs that had unanticipated side effects. The cost of any product liability litigation or other proceedings, even if resolved in our favor, could be substantial, particularly in light of the size of our business and financial resources. A product liability claim or series of claims brought against us could cause our share price to decline and, if we are unsuccessful in defending such a claim or claims and the resulting judgments exceed our insurance coverage, our financial condition, business and prospects could be materially adversely affected.

Our ability to use our net operating losses to offset future taxable income may be subject to certain limitations.

Our ability to use our net operating losses (‘NOLs’ or ‘tax losses’) in the Netherlands is currently limited and may be further limited. Under Dutch income tax law, effective from January 1, 2022, tax losses may be carried forward indefinitely. However, the offset of losses will be limited in a given year against the first € 1.0 million of taxable profit. For taxable profit in excess of this amount, losses may only be offset up to 50% of this excess. As at December 31, 2022, we had a total of € 377.9 million tax loss carry-forwards available for offset against future taxable profits.

There is also a risk that due to regulatory changes such as suspensions on the use for NOLs, our existing NOLs could expire or otherwise become unavailable to offset future income tax liabilities. For these reasons, we may not be able to use a material portion of the NOLs, even if we attain profitability.

Changes in accounting rules and regulations, or interpretations thereof, could result in unfavorable accounting charges or require us to change our compensation policies.

Accounting methods and policies for biopharmaceutical companies, including policies governing revenue recognition, research and development and related expenses and accounting for share-based compensation, are subject to review, interpretation and guidance from relevant accounting authorities, as well as the SEC. Changes to accounting methods or policies, or interpretations thereof, may require us to reclassify, restate or otherwise change or revise our financial statements, including those contained in this Annual Report.

Risks Related to Ownership of our Ordinary Shares

We cannot predict what the market price of our ordinary shares will be. As a result, it may be difficult for investors to sell our ordinary shares at or above the price at which they purchased them.

An active trading market for our shares may not be sustained. The market value of our ordinary shares may decrease from time to time. As a result of these and other factors, investors may be unable to resell our shares at or above the price at which they purchased them. The lack of an active market may impair investors’ ability to sell our shares at the time they wish to sell them or at a price that they consider reasonable. The lack of an active market may also reduce the fair market value of our shares. Further, an inactive market may also impair our ability to raise capital by selling our ordinary shares and may impair our ability to enter into strategic partnerships or acquire companies or products by using our ordinary shares as consideration. The market price of our shares may be volatile and investors could lose all or part of their investment.

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The trading price of our ordinary shares is likely to be highly volatile and could be subject to wide fluctuations in response to various factors, some of which are beyond our control. For example, the price of our ordinary shares, which reached its high record of $ 27.60 per share at the close of the trading on March 16, 2015, decreased as low as $ 0.56 per share at the close of the trading on May 11, 2022. In addition to the factors discussed in this “Risk Factors” section and elsewhere in this Annual Report, these factors include:

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In addition, the stock market in general, and pharmaceutical and biotechnology companies in particular, have experienced extreme price and volume fluctuations that have sometimes been unrelated or disproportionate to the operating performance of these companies. Broad market and industry factors may negatively affect the market price of our ordinary shares, regardless of our actual operating performance. The realization of any of the above risks or any of a broad range of other risks, including those described in these “Risk Factors,” could have a dramatic and material adverse impact on the market price of our ordinary shares.

If we are unable to maintain compliance with Nasdaq listing standards, our ordinary shares may be delisted from the Nasdaq Stock Market and you may face significant restrictions on the resale of your shares.

There can be no assurances that we will be able to maintain our Nasdaq listing in the future. For example, in May 2022, we received a notification from Nasdaq that the trading price of our ordinary shares did not meet the minimum bid price requirement of $1.00 per share for a period of 30 consecutive trading days. We were granted a 180-day compliance period to regain compliance by achieving a closing bid price of at least $1.00 per share for a minimum of 10 consecutive trading days. In October 2022, we transferred our listing from the Nasdaq Global Market to the Nasdaq Capital Market and received an additional 180-day compliance period, as contemplated by Nasdaq. On December 2, 2022, Nasdaq informed us that we had regained compliance with the minimum bid price rule. Nevertheless, share prices in biotech are volatile and there can be no assurances that we will be able to maintain our Nasdaq Capital Market listing in the future.

In the event we are unable to maintain compliance with the Nasdaq Capital Market listing standards and our ordinary shares are delisted from the exchange, it would, among other things, likely lead to a number of negative implications, including an adverse effect on the price of our ordinary shares, reduced liquidity in our ordinary shares, the loss of federal preemption of state securities laws, breach of covenants in agreements and greater difficulty in obtaining financing. In the event of a de-listing, we would take actions to restore our compliance with Nasdaq’s listing requirements, but we can provide no assurance that any such action taken by us would allow our ordinary shares to become listed again, stabilize the market price or improve the liquidity of our ordinary shares, prevent our ordinary shares from dropping below the Nasdaq minimum bid price requirement in the future, or prevent future non-compliance with Nasdaq’s listing requirements. If we cannot restore our compliance with Nasdaq’s listing requirements, we would pursue eligibility for trading of these securities on other markets or exchanges, such as the OTCQB or OTCQX, which are unorganized, inter-dealer, over-the-counter markets which provides significantly less liquidity than the Nasdaq Capital Market or other national securities exchanges.

Unstable market and economic conditions may have serious adverse consequences on our business, financial condition and trading price of our ordinary shares.

The global credit and financial markets have experienced extreme volatility and disruptions in the past several years, including severely diminished liquidity and credit availability, declines in consumer confidence, declines in economic growth, increases in unemployment rates and uncertainty about economic stability. We believe that the state of global economic conditions remain particularly volatile and uncertain, the impact of fiscal stimulus programs initiated by various governments in response to the pandemic and economic downturn and ongoing supply chain issues and inflationary pressures, but also due to recent and expected shifts in political, legislative and regulatory conditions concerning, among other matters, international trade and taxation, and that an uneven recovery or a renewed global downturn may negatively impact our ability to conduct clinical trials on the scale and timelines anticipated. There can be no assurance that further deterioration in credit and financial markets and confidence in economic conditions will not occur. Our general business strategy may be adversely affected by any such economic downturn, volatile business or political environment or continued unpredictable and unstable market conditions. If the current equity and credit markets deteriorate, it may make obtaining any necessary debt or equity financing more difficult, more costly and more dilutive. Failure to secure any necessary financing in a timely manner and on favorable terms could have a material adverse effect on our growth strategy, financial performance and stock price and could require us to delay or abandon clinical development plans. In addition, there is a risk that one or more of our current service providers, manufacturers and other partners may not survive an economic downturn, which could directly affect our ability to attain our operating goals on schedule and on budget. To the extent that our profitability and strategies are negatively affected by downturns or volatility in general economic conditions, our business and results of operations may be materially adversely affected.

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If securities or industry analysts publish inaccurate or unfavorable research or cease to publish research about our business, our share price and trading volume could decline.

The trading market for our ordinary shares depends in part on the research and reports that securities or industry analysts publish about us or our business. In the event securities or industry analysts who cover us downgrade our ordinary shares, or publish inaccurate or unfavorable research about our business, our share price would likely decline. In addition, if one or more of these analysts cease coverage of our company or fail to publish reports on us regularly, demand for our ordinary shares could decrease, which might cause our share price and trading volume to decline.

Sales of a substantial number of our ordinary shares by our existing shareholders in the public market could cause our share price to fall.

If our existing shareholders sell, or indicate an intention to sell, substantial amounts of our ordinary shares in the public market, the trading price of our ordinary shares could decline. In addition, a substantial number of ordinary shares subject to outstanding options are or will become eligible for sale in the public market to the extent permitted by the provisions of various vesting schedules. If these additional ordinary shares are sold, or if it is perceived that they will be sold, in the public market, the trading price of our ordinary shares could decline.

If we sell our ordinary shares in future financings, shareholders may experience immediate dilution and, as a result, our share price may decline.

We may from time to time issue additional ordinary shares or securities convertible into our ordinary shares, including in future financings that we may undertake. For example, in December 2022, we issued 9,381,586 shares to Lilly pursuant to our expanded licensing and research collaboration with Lilly, resulting in gross proceeds of € 14,122,000. In September 2021, the Company issued 3,989,976 shares to Lilly pursuant to the original collaboration, resulting in gross proceeds of € 23,223,000. In April 2021, the Company consummated an underwritten public offering of 15,923,077 ordinary shares at an issue price of $ 6.50 per share. The gross proceeds from this offering amounted to € 88,115,000.

In November 2021, we entered into a sales agreement for at-the-market offerings up to a maximum aggregate offering price of $75,000,000 of our ordinary shares with Cantor Fitzgerald & Co.

In September 2022, ProQR extinguished its debt with Pontifax Medison Finance and Kreos Capital by repaying all outstanding principal amounts and interest accrued thereon. In connection with our prior loan facility with Pontifax and Kreos, we issued warrants to purchase up to an aggregate of 679,628 ordinary shares, with exercise prices ranging between $7.00 and $12.00. These warrants remain in place until their five-year economic life expires.

Due to the issuances described above and any future additional issuances of shares of our common stock or securities convertible into common stock, including pursuant to our shelf registration statement or our ATM facility, our shareholders may experience immediate dilution and, as a result, our stock price may decline.

Because we do not anticipate paying any cash dividends on our ordinary shares in the foreseeable future, capital appreciation, if any, will be the sole source of potential gain for our shareholders.

We have never declared or paid cash dividends on our ordinary shares. We currently intend to retain all of our future earnings, if any, to finance the growth and development of our business. As a result, capital appreciation, if any, of our ordinary shares will be the sole source of gain for our shareholders for the foreseeable future.

We have been a listed company since September 2014. Complying with all requirements will increase our costs, require additional management resources and qualified accounting and financial personnel, and we may fail to meet all of these obligations.

We face substantial legal, accounting, administrative and other costs and expenses as a public company. Compliance with the Sarbanes-Oxley Act of 2002, the Dodd-Frank Act of 2010, the Dutch Financial Supervision Act and the rules promulgated thereunder, as well as rules of the SEC and Nasdaq and the Dutch Corporate Governance Code (DCGC) for example, are expected to result in ongoing increases in our legal, audit and financial compliance costs. The Securities

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Exchange Act of 1934, as amended (the Exchange Act) requires, among other things, that we file certain periodic reports with respect to our business and financial condition. We must also comply with the auditor attestation requirements of Section 404 of the Sarbanes-Oxley Act of 2002. Complying with Section 404 is costly and management’s attention may be diverted from other business concerns, which could adversely affect our business and results of operations.

We currently do not have an internal audit group, and we will need to continue to hire additional accounting and financial staff with appropriate public company experience and technical accounting knowledge, and it may be difficult to recruit and maintain such personnel. Implementing any appropriate changes to our internal controls may require specific compliance training for our directors, officers and employees, entail substantial costs to modify our existing accounting systems, and take a significant period of time to complete. Such changes may not, however, be effective in maintaining the adequacy of our internal controls, and any failure to maintain that adequacy, or consequent inability to produce accurate financial statements or other reports on a timely basis, could increase our operating costs and could materially impair our ability to operate our business.

If we fail to establish and maintain an effective system of internal control over financial reporting, we may not be able to accurately report our financial results or prevent fraud. As a result, shareholders could lose confidence in our financial and other public reporting, which would harm our business and the trading price of our ordinary shares.

Effective internal controls over financial reporting are necessary for us to provide reliable financial reports and, together with adequate disclosure controls and procedures, are designed to prevent fraud. Any failure to implement required new or improved controls, or difficulties encountered in their implementation, could cause us to fail to meet our reporting obligations. In addition, any testing by us conducted in connection with Section 404 of the Sarbanes-Oxley Act of 2002, or any subsequent testing by our independent registered public accounting firm, may reveal deficiencies in our internal controls over financial reporting that are deemed to be material weaknesses or that may require prospective or retroactive changes to our financial statements or identify other areas for further attention or improvement. Inferior internal controls could also cause investors to lose confidence in our reported financial information, which could have a negative effect on the trading price of our ordinary shares.

Our management board is required to assess the effectiveness of our internal controls and procedures annually and, in case we become a domestic filer, we will be required to disclose changes to these controls on a quarterly basis. Our independent registered public accounting firm is required to attest to the effectiveness of our internal controls over financial reporting pursuant to Section 404. An independent assessment of the effectiveness of our internal controls could detect problems that our management’s assessment might not. Undetected material weaknesses in our internal controls could lead to financial statement restatements and require us to incur the expense of remediation.

Our disclosure controls and procedures may not prevent or detect all errors or acts of fraud.

We are subject to certain reporting requirements of the Exchange Act. Our disclosure controls and procedures are designed to reasonably assure that information required to be disclosed by us in reports we file or submit under the Exchange Act is accumulated and communicated to management, recorded, processed, summarized and reported within the time periods specified in the rules and forms of the SEC. We believe that any disclosure controls and procedures or internal controls and procedures, no matter how well conceived and operated, can provide only reasonable, not absolute, assurance that the objectives of the control system are met. These inherent limitations include the realities that judgments in decision-making can be faulty, and that breakdowns can occur because of simple error or mistake. Additionally, controls can be circumvented by the individual acts of some persons, by collusion of two or more people or by an unauthorized override of the controls. Accordingly, because of the inherent limitations in our control system, misstatements or insufficient disclosures due to error or fraud may occur and not be detected.

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Risks Related to Investing in a Foreign Private Issuer or a Dutch Company

We are a foreign private issuer and, as a result, we are not subject to U.S. proxy rules and are subject to Exchange Act reporting obligations that, to some extent, are more lenient and less frequent than those of a U.S. domestic public company.

We report under the Exchange Act as a non-U.S. company with foreign private issuer status. Because we qualify as a foreign private issuer under the Exchange Act and although we are subject to Dutch laws and regulations with regard to such matters and intend to furnish quarterly financial information to the SEC, we are exempt from certain provisions of the Exchange Act that are applicable to U.S. domestic public companies, including:

In addition, foreign private issuers are not required to file their annual report on Form 20-F until 120 days after the end of each fiscal year, while U.S. domestic issuers that are accelerated filers are required to file their annual report on Form 10-K within 75 days after the end of each fiscal year. Foreign private issuers are also exempt from the Regulation Fair Disclosure, aimed at preventing issuers from making selective disclosures of material information. As a result of the above, our shareholders may not have the same protections afforded to shareholders of companies that are not foreign private issuers.

Certain U.S. holders of our ordinary shares may suffer adverse tax consequences if we are characterized as a passive foreign investment company for U.S. federal income tax purposes.

Generally, if, for any taxable year, at least 75% of our gross income is passive income, or at least 50% of the value of our assets is attributable to assets that produce passive income or are held for the production of passive income, including cash, we would be characterized as a passive foreign investment company (PFIC) for U.S. federal income tax purposes. For purposes of these tests, passive income includes dividends, interest, and gains from the sale or exchange of investment property and rents and royalties other than rents and royalties which are received from unrelated parties in connection with the active conduct of a trade or business. If we are characterized as a PFIC, our U.S. shareholders may suffer adverse tax consequences, including having gains realized on the sale of our ordinary shares treated as ordinary income, rather than capital gain, the loss of the preferential rate applicable to dividends received on our ordinary shares by individuals who are U.S. holders, and having interest charges apply to distributions by us and the proceeds of share sales. See Item 10.E: “Taxation” for more information.

The market value of our assets may be determined in large part by reference to the market price of our ordinary shares, which is likely to fluctuate and may fluctuate considerably given that market prices of technology companies have been especially volatile. In addition, the composition of our income and assets will be affected by how, and how quickly, we spend our cash, including any cash raised pursuant to prior offerings. Based on the average value of our gross assets and composition of our income, we believe that we were a PFIC for the 2022 taxable year. However, our status as a PFIC is a fact-intensive determination made on an annual basis, and we cannot provide any assurance regarding our PFIC status for the current, prior or future taxable years.

We intend to provide the information necessary for U.S. holders to make a “qualified electing fund,” (QEF) election if we are treated as a PFIC for any taxable year.

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The rights and responsibilities of our shareholders are governed by Dutch law and differ in some important respects from the rights and responsibilities of shareholders under U.S. law.

Our corporate affairs are governed by our articles of association, our internal rules and by the laws governing companies incorporated in the Netherlands. The rights of our shareholders and the responsibilities of members of our supervisory board under Dutch law are different than under the laws of some U.S. jurisdictions. In the performance of their duties, our management board and our supervisory board are required by Dutch law to consider the interests of ProQR Therapeutics, its shareholders, its employees and other stakeholders and not only those of our shareholders. Also, as a Dutch company, we are not required to solicit proxies or prepare proxy statements for general meetings of shareholders. Dutch law does not have a regulatory regime for U.S.-style proxy solicitations and, even though Dutch law accommodates voting by proxy, the solicitation of proxies is not a widely used business practice in the Netherlands. In addition, the rights of holders of shares and many of the rights of shareholders as they relate to, for example, the exercise of shareholder rights, are governed by Dutch law and our articles of association and differ from the rights of shareholders under U.S. law. For example, Dutch law does not grant appraisal rights to a company’s shareholders who wish to challenge the consideration to be paid upon a merger or consolidation of the company.

We may lose our foreign private issuer status which would then require us to comply with the Exchange Act’s domestic reporting regime and cause us to incur significant legal, accounting and other expenses.

We are a foreign private issuer and therefore we are not required to comply with all of the periodic disclosure and current reporting requirements of the Exchange Act applicable to U.S. domestic issuers. In order to maintain our current status as a foreign private issuer, either:

If we lose this status, we would be required to comply with the Exchange Act reporting and other requirements applicable to U.S. domestic issuers, which are more detailed and extensive than the requirements for foreign private issuers.

We may also be required to make changes in our corporate governance practices in accordance with various SEC and Nasdaq rules. The regulatory and compliance costs to us under U.S. securities laws if we are required to comply with the reporting requirements applicable to a U.S. domestic issuer may be significantly higher than the costs we would incur as a foreign private issuer. As a result, we expect that a loss of foreign private issuer status would increase our legal and financial compliance costs, would make some activities more time consuming and costly and could necessitate the hiring of additional accounting, financial and legal staff. We also expect that if we were required to comply with the rules and regulations applicable to U.S. domestic issuers, it would make it more difficult and expensive for us to obtain director and officer liability insurance, and we may be required to accept reduced coverage or incur substantially higher costs to obtain coverage. These rules and regulations could also make it more difficult for us to attract and retain qualified members of our supervisory board.

We currently report our financial results under IFRS, which differ in certain significant respects from U.S. GAAP.

Currently we report our financial statements under International Financial Reporting Standards (IFRS). There have been and there may in the future be certain significant differences between IFRS and U.S. GAAP, including differences related to revenue recognition, share-based compensation expense, income tax and earnings per share. As a result, our financial information and reported earnings for historical or future periods could be significantly different if they were prepared in accordance with U.S. GAAP. In addition, we do not intend to provide a reconciliation between IFRS and U.S. GAAP unless it is required under applicable law. As a result, you may not be able to meaningfully compare our financial statements under IFRS with those companies that prepare financial statements under U.S. GAAP.

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Provisions of our articles of association or Dutch corporate law might deter acquisition bids for us that might be considered favorable and prevent or frustrate any attempt to replace or remove the management board and supervisory board.

Certain provisions of our articles of association may make it more difficult for a third party to acquire control of us or effect a change in our management board or supervisory board. These provisions include:

In addition, under Dutch law, our management board and supervisory board need to act in the interest of the company and our business. The boards are required to take into account the interests of all our stakeholders, including by promoting the sustainable success of our business and the creation of long term value for us and our business. The boards are responsible for determining our strategy and choosing our strategic direction. In doing so and depending on the circumstances they may decide to not entertain a proposed takeover or other strategic proposal, even if the proposal is supported by the majority of our shareholders and/or would create more shareholder value. The boards may also use their general authority under Dutch corporate law and the Dutch Corporate Governance Code (the DCGC) to use (ad-hoc) defensive mechanisms against and/or not co-operate with a proposal, e.g., by not providing due diligence and or by not cooperating with shareholder proposals to adopt resolutions in a general shareholder meeting that may change our strategy. The boards may for instance invoke the maximum 180 days response time set out in the DCGC and/or the Dutch statutory reflection period of up to 250 days in response to shareholder activists seeking changes in the composition of the boards and/or upon hostile takeover attempts.

As indicated above, we have adopted an anti-takeover measure by granting a perpetual and repeatedly exercisable call option to the protection foundation, which confers upon the protection foundation the right to acquire, under certain conditions, the number of preferred shares described above. The issuance of such preferred shares will occur upon the protection foundation’s exercise of the call option and will not require shareholder consent. Such a measure has the effect of making a takeover of us more difficult or less attractive and as a result, our shareholders may be unable to benefit from a change of control and realize any potential change of control premium which may materially and adversely affect the market price of our ordinary shares.

We are not obligated to and do not comply with all the best practice provisions of the Dutch Corporate Governance Code. This may affect our shareholders’ rights.

As a Dutch company we are subject to the Dutch Corporate Governance Code (DCGC). The DCGC contains both principles and best practice provisions that regulate relations between the management board, the supervisory board and the shareholders (i.e., the general meeting of shareholders). The DCGC is based on a “comply or explain” principle. Accordingly, companies are required to disclose in their annual reports, filed in the Netherlands, whether they comply

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with the provisions of the DCGC. If they do not comply with those provisions (e.g., because of a conflicting Nasdaq requirement), we are required to give the reasons for such non-compliance.

The DCGC applies to all Dutch companies listed on a government-recognized stock exchange, whether in the Netherlands or elsewhere, including Nasdaq. We do not comply with all the best practice provisions of the DCGC. This may affect our shareholders’ rights and they may not have the same level of protection as a shareholder in a Dutch company that fully complies with the DCGC.

We intend to rely in certain cases on Nasdaq Stock Market rules that permit us to comply with applicable Dutch corporate governance practices, rather than the corresponding domestic U.S. corporate governance practices, and therefore our shareholders’ rights will differ from the rights they would have as a shareholder of a domestic U.S. issuer.

As a foreign private issuer whose ordinary shares are listed on the Nasdaq Capital Market, we are permitted in certain cases to follow Dutch corporate governance practices instead of the corresponding requirements of the Nasdaq Marketplace Rules. A foreign private issuer that elects to follow a home country practice instead of Nasdaq requirements must submit to Nasdaq in advance a written statement from an independent counsel in such issuer’s home country certifying that the issuer’s practices are not prohibited by the home country’s laws. In addition, a foreign private issuer must disclose in its annual reports filed with the SEC each such requirement that it does not follow and describe the home country practice followed instead of any such requirement. We intend to follow Dutch corporate governance practices with regard to the quorum requirements applicable to meetings of shareholders and the provision of proxy statements for general meetings of shareholders, rather than the corresponding domestic U.S. corporate governance practices. In accordance with Dutch law and generally accepted business practices, our articles of association do not provide quorum requirements (other than those which follow from Dutch law) generally applicable to general meetings of shareholders. Although we do intend to provide shareholders with an agenda and other relevant documents for the general meeting of shareholders, Dutch law does not have a regulatory regime for the solicitation of proxies and the solicitation of proxies is not a generally accepted business practice in the Netherlands. Accordingly, our shareholders may not be afforded the same protection as provided under Nasdaq’s corporate governance rules.

Any U.S. or other foreign judgments that investors may obtain against us may be difficult to enforce against us in the Netherlands.

We are incorporated under the laws of the Netherlands. We currently have only limited operations in the United States. Most of our assets are currently located in the Netherlands. The majority of our management board, supervisory board and officers reside outside the United States. As a result, it may not be possible for investors to effect service of process within the United States upon such persons or to enforce against them or the Company in U.S. courts, including judgments predicated upon the civil liability provisions of the federal securities laws of the United States. In addition, it is not clear whether a Dutch court would impose civil liability on the Company or any of our managing directors or supervisory directors in an original action based solely upon the federal securities laws of the United States brought in a court of competent jurisdiction in the Netherlands.

The United States and the Netherlands currently do not have a treaty providing for the reciprocal recognition and enforcement of judgments, other than arbitration awards, in civil and commercial matters. Consequently, a final judgment for payment given by a court in the United States, whether or not predicated solely upon U.S. securities laws, would not automatically be recognized or enforceable in the Netherlands. In order to obtain a judgment which is enforceable in the Netherlands, the party in whose favor a final and conclusive judgment of the U.S. court has been rendered will be required to file its claim with a court of competent jurisdiction in the Netherlands. Such party may submit to the Dutch court the final judgment rendered by the U.S. court. If and to the extent that the Dutch court finds that the jurisdiction of the U.S. court has been based on grounds which are internationally acceptable and that proper legal procedures have been observed, the Dutch court will, in principle, give binding effect to the judgment of the U.S. court, unless such judgment contravenes principles of public policy of the Netherlands. Dutch courts may deny the recognition and enforcement of punitive damages or other awards. Moreover, a Dutch court may reduce the amount of damages granted by a U.S. court and recognize damages only to the extent that they are necessary to compensate actual losses or damages. Enforcement and recognition of judgments of U.S. courts in the Netherlands are solely governed by the provisions of the Dutch Code of Civil Procedure.

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Based on the lack of a treaty as described above, U.S. investors may not be able to enforce against us or our management board or supervisory board members, representatives or certain experts named herein who are residents of the Netherlands or countries other than the United States any judgments obtained in U.S. courts in civil and commercial matters, including judgments under the U.S. federal securities laws.

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Item 4: Information on the Company

A. History and Development of the Company

ProQR Therapeutics is a biotechnology company dedicated to changing lives by developing RNA therapies for severe rare and common diseases. We focus on advancing our proprietary Axiomer® RNA-editing platform technology.

ProQR was founded in 2012 by Daniel de Boer, Gerard Platenburg, the late Henri Termeer and Dinko Valerio. Since September 18, 2014, our ordinary shares have been listed on Nasdaq. They are currently trading on Nasdaq Capital Market under the ticker symbol “PRQR”. As of December 31, 2022, we had raised € 435 million in gross proceeds from our public offerings of shares and private placements of equity securities. In addition, we have received grants, loans and other funding from patient organizations, private lenders and government institutions supporting our programs, including from Foundation Fighting Blindness and the Dutch government under the innovation credit program.

Our legal name is ProQR Therapeutics N.V. and we were incorporated in the Netherlands on February 21, 2012. We reorganized from a private company with limited liability to a public company with limited liability on September 23, 2014. Our company is registered with the Dutch Trade Register of the Chamber of Commerce (handelsregister van de Kamer van Koophandel) under number 54600790. Our corporate seat is in Leiden, the Netherlands. The address of our headquarters and registered office is Zernikedreef 9, 2333 CK Leiden, the Netherlands, telephone number +31 88 166 7000. Our U.S. office is located at 245 Main Street, Cambridge, MA 02142, USA. The name and address of our agent for service in the United States is Andrew Morris, 245 Main Street, Cambridge, MA 02142, USA.

The SEC maintains an internet site that contains reports, proxy and information statements, and other information regarding issuers like ProQR that file electronically with the SEC. The address of that website is www.sec.gov. We maintain a corporate website at www.ProQR.com. Information found on, or accessible through, our website is not incorporated by reference into and should not be considered a part of this Annual Report, and the reference to our website in this Annual Report is an inactive textual reference only.

B. Business Overview

We are a biotechnology company dedicated to the creation of transformative RNA therapies to improve the lives of patients and families affected by diseases with high unmet medical need. To achieve this, we are advancing our proprietary Axiomer® RNA-editing platform technology. We believe that drugs that work through this mechanism of RNA editing have the potential to become a new class of innovative medicines with applicability to a broad range of therapeutic areas. Using our deep RNA expertise and our strong intellectual property position, we are advancing a platform to develop these RNA editing therapeutics, which we call “Editing Oligonucleotides”, or EONs, for a variety of human diseases.

Axiomer uses EONs to mediate single nucleotide changes to RNA in a highly specific and targeted way using molecular machinery that is present in human cells called ADAR (Adenosine Deaminase Acting on RNA). Axiomer EONs are designed to recruit and direct endogenously expressed ADARs to change an Adenosine (A) to an Inosine (I) in the RNA – an Inosine is translated as a Guanosine (G). This approach can be used to correct an RNA with a disease-causing mutation back to a normal (wild type) RNA, introduce mutations to prevent disease, modulate protein expression, or alter a protein so that it will have a new function that helps prevent or treat disease.

Since discovering the Axiomer RNA editing technology in 2014, we have established a leading intellectual property estate in the ADAR editing space, defined the design ground rules, and optimized chemistries for therapeutic use.

Our research and development strategy focuses on use of our Axiomer platform to develop novel RNA editing therapeutics to address diseases with high unmet medical need. We are initially focused on diseases originating in the

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liver where research into human genetics has shown us that introduction or correction of a mutation may lead to a benefit for patients. We prioritize areas with well-established biomarkers for the assessment of early clinical activity and to establish proof of target engagement, established clinically relevant endpoints, and the ability to leverage existing proven delivery technology. We are advancing AX-0810 for cholestatic diseases targeting Na-taurocholate cotransporting polypeptide, or NTCP, and AX-1412 for cardiovascular disease targeting Beta-1,4-galactosyltransferase 1, or B4GALT1, as our initial pipeline programs.

In addition to advancing our wholly-owned pipeline programs, we entered into a global licensing and research collaboration with Eli Lilly and Company in September 2021 where our Axiomer RNA editing platform is being used to progress new drug targets for disorders toward clinical development and commercialization. Initially focused on five targets, the partnership was expanded to ten targets in December 2022, with an option for further expansion to fifteen targets.

We believe the platform has significant potential to yield many additional therapeutic candidates. Thus, we continuously evaluate further opportunities for beneficial collaborations or strategic partnerships to efficiently advance product candidates with the goal of bringing medicines to patients.

We have other earlier stage RNA editing platform technologies, including our Trident platform. Our Trident RNA pseudouridylation platform is designed to enable the suppression of nonsense mutations and premature stop codons (PTC) that cause 11% of all human genetic diseases. Since all premature stop codons contain uridine, pseudouridylation of that uridine converts those nonsense codons into sense codons. The Trident technology harnesses the endogenously expressed pseudouridylation machinery with guide RNAs to inhibit nonsense messenger RNA (mRNA)-mediated decay (NMD) in a sequence-specific manner and promote PTC readthrough. The Trident technology has the potential to be applied in genetic diseases caused by PTCs.

Both the Axiomer and Trident RNA editing platforms are novel, proprietary RNA technologies invented at ProQR or with our academic collaborators. We have built a broad intellectual property estate around these technologies and together with the leading academic experts in the RNA field, we continue to advance these technologies.

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RNA editing for therapeutic applications

RNA antisense oligonucleotides (AONs) have been used as therapeutics for the last few decades. ProQR scientists have invented entirely new ways of using the proven modality of oligonucleotides to recruit a novel mechanism of action.

RNAs are produced in a process called transcription, where genetic information in DNA is copied into RNA. The information in RNA then serves as a blueprint to produce a protein via a process called translation. Before translation occurs, RNA can be processed in several ways. One way is RNA editing, which involves changing specific nucleotides, or letters, in the RNA code. RNA editing is a naturally occurring process that helps ensure that produced proteins function normally. It can also create slightly differently functioning proteins.

One common type of RNA editing is A-to-I editing, where Adenosines (abbreviated as A), are changed into Inosines (abbreviated as I), as shown in Figure 1. Nucleotides pair together to create double stranded structures within the RNA. Double stranded RNA structures are found and bound to by ADAR, which is naturally present in the cells. ADAR then can edit As into Is, which is read by a ribosome as a G, or guanosine. This process is called “A to I”editing, which functionally enables changing an A into a G. In 2014, scientists at ProQR invented Axiomer, which was conceived based on the idea of recruiting endogenous ADAR in humans to make single A to I changes in RNA in a highly specific and targeted manner, using EONs as shown in Figure 1b.

Figure 1a: RNA editing is a naturally occurring process whereby ADARs perform A to I editing.

Figure 1b: ProQR’s Axiomer RNA editing technology platform uses EONs to recruit and direct endogenously expressed ADARs to edit an A to an I in the RNA, which is then translated as a G, allowing highly specific editing.
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There are over 16 million known locations in the RNA where ADARs perform A to I editing throughout the body, which we believe represents a powerful potential therapeutic mechanism for multiple disease areas. Axiomer could potentially yield a new class of medicines for both rare and prevalent diseases with unmet need.

Our Strategy

We are advancing Axiomer as a platform to develop a new class of innovative medicines based on RNA editing, which we believe has the potential to treat a broad range of diseases that currently lack adequate treatment options. Our novel and proprietary RNA editing platform technologies, known as Axiomer and Trident, are new ways to use oligonucleotides to edit single nucleotides in the RNA. We believe the Axiomer technology may be applicable to more

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than 20,000 disease-causing mutations and is designed to make changes to protein function and therefore has potentially broad applicability to genetic and non-genetic diseases. Beyond mutation correction, Axiomer also has the potential to modulate protein expression or alter a protein so that it will have a new function to help prevent or treat disease. We intend to continue to optimize our platform as we advance to clinical stage and beyond. Key elements of our strategy include:

We seek to maximize the value of our pipeline by retaining development and commercialization rights to those product candidates, indications and geographies that we believe we can independently develop, seek approval for, and commercialize on our own. Beyond this, for other product candidates, such as those for more prevalent indications, indications and geographies, we plan to selectively and opportunistically seek potential partnerships following early-stage clinical proof of concept.

Our Novel Axiomer RNA Editing Technology Platform

Antisense oligonucleotides, or AONs, have been used as therapeutics for the last few decades. Our Axiomer RNA editing technology is based on editing oligonucleotides, or EONs, designed to recruit endogenous ADAR enzymes (Adenosine Deaminases Acting on RNA) to make single adenosine-to-inosine (A-to-I) changes in the RNA in a highly specific and targeted manner. This technology could reverse the more than 20,000 G-to-A mutations in the human population that cause disease. In vitro and in vivo work indicates that the EONs are generally applicable for the correction of mRNA G-to-A mutations. The technology is also designed to modulate protein expression or alter proteins to provide a new function to help prevent or treat disease. With this applicability, we believe Axiomer has the potential to address hundreds or more of genetic and non-genetic diseases.

Across a range of targets, we have shown both in vitro and in vivo platform proof-of-concept for our Axiomer RNA editing technology platform, including cell models, organoids, and animal models, including relevant higher order species.

For example, in a variety of nervous system targets, Axiomer has demonstrated proof of concept across multiple models, as shown in Figure 2. Specifically, up to 40% editing in vivo has been observed in mice models and up to 50% editing in vivo has been reported in non-human primate (NHP).

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Figure 2: In the nervous system, consistent editing with Axiomer editing oligonucleotides reported across different models and targets in vivo including non-human primate.

In a variety of targets relevant for liver-originating disease, Axiomer has demonstrated proof of concept across multiple models, as shown in Figure 3. Specifically, up to 50% editing in vivo has been demonstrated in mice liver target models with research in NHP models ongoing.

If translated in human testing, we believe this editing activity supports the potential of our technology and plan to advance product candidates based on our Axiomer platform to clinical stage.

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Figure 3: In a range of liver targets in vitro and in vivo editing activity was observed with Axiomer editing oligonucleotides.

Our Pipeline

We are advancing Axiomer as a platform to develop a new class of innovative medicines based on RNA editing. Our initial pipeline targets focus on liver-originating disease and share several key characteristics, including:

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Our initial pipeline programs include AX-0810 for Cholestatic Diseases targeting NTCP and AX-1412 for Cardiovascular Disease targeting B4GALT1. Over the next 12 months we plan to present non-clinical proof-of-concept data for these programs and over the next 18 months we anticipate providing an update on translational data to enable progression into CTA. We expect to advance these programs to clinical trials in late 2024 / early 2025.

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AX-0810 for Cholestatic Diseases targeting NTCP

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Cholestatic diseases overview

Cholestatic disorders are caused by a buildup of bile acids in the liver due to bile duct dysfunction, which causes liver cell damage. The consequences of these disorders can be devastating and significantly impact a person's quality of life, including pruritus, dry skin, fatigue, pain, weight loss, and many others. Without treatment, the damage progresses through various stages, from fibrosis to cirrhosis, ultimately leading to liver failure and an increased risk of liver cancer. Liver transplants are often necessary for primary sclerosing cholangitis (PSC) and biliary atresia (BA), two forms of cholestatic disease with high unmet medical needs.

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PSC is a condition that causes inflammation and is typically diagnosed in people aged 30 to 40, more commonly affecting men (66%). It is estimated that 80,000 people in North America and Europe have PSC, with a prevalence of 1 to 9

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individuals per 100,000. This condition causes fibrosis and sclerosis of bile ducts, leading to a toxic buildup of bile acids in the liver.

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BA is a pediatric condition that affects newborns, resulting from the absence or defect of bile ducts. This condition causes harmful bile acids to accumulate in the liver, leading to rapid progression to cirrhosis early in life. It is estimated that 20,000 individuals in North America and Europe have BA, with a prevalence of 1 in 10,000 to 15,000 births in the western world.

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Limitations of the Current Treatment Landscape

Currently, there are no approved drugs for treating PSC and BA. For PSC, liver transplantation is the only treatment option with evidence to extend survival. However, PSC can return in 20 to 40% of patients who undergo liver transplantation, and the median survival without a transplant is only 21 years. Surgery in the first weeks of life for BA is the gold standard treatment. However, most patients who receive this surgery will still require a liver transplant early in life.

AX-0810 for Cholestatic Diseases targeting NTCP

The liver cells mainly obtain bile acids from the enterohepatic reuptake cycle. The process is primarily carried out by a transporter called Na-taurocholate transporting polypeptide (NTCP, SLC10A1), which takes bile acids from the portal circulation to the liver. Studies show that inhibiting NTCP can improve liver function by reducing the levels of toxic bile acids, improving liver damage markers (fibrosis, cholangiocyte proliferation, Alkaline phosphatase or ALP, alanine transaminase or ALT), and lowering inflammation biomarkers (cytokines).

AX-0810, our Axiomer-targeted RNA editing oligonucleotide, aims to reduce the reabsorption of bile acids in the liver by inhibiting NTCP function. Loss of function (LOF) variants in NTCP naturally occur in some people without causing any symptoms associated with cholestasis. This finding suggests that our approach is safe and may reduce the accumulation of toxic bile acids in the liver. Moreover, LOF variants in NTCP also promote the elimination of bile acids from the body by increasing their excretion in the feces and urine, a process called sulfation of bile acids, which enhances their solubility and reduces their absorption in the intestines. Based on its mechanism of action, we believe AX-0810 may have the potential to modify the course of cholestatic diseases, delay or prevent complications such as cirrhosis and liver failure, and alleviate associated symptoms.

AX-1412 for Cardiovascular Disease targeting B4GALT1

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Cardiovascular disease overview

Cardiovascular diseases (CVDs) are a group of health conditions that affect the heart and blood vessels, such as atherosclerosis which can lead to severe problems like heart attacks, heart failure, and stroke. The World Health Organization (WHO) has identified unhealthy diet, physical inactivity, tobacco use, and excessive alcohol consumption as major behavioral risk factors for heart disease and stroke, increasing intermediate risk factors including but not limited to high blood pressure, cholesterol, glucose levels, and obesity.

CVDs are the leading cause of disability and death globally, becoming a significant health issue worldwide. Approximately 18 million people die from CVDs each year, making up 32% of all global deaths, according to a report by the World Health Organization in 2021. In the United States, the American Heart Association estimates that by 2035, more than 130 million adults will have some form of CVD.

Current Treatment Landscape and Limitations

CVD treatment involves taking medications to lower cholesterol and blood pressure levels. The most common drugs are statins, ezetimibe, and PCSK9 inhibitors. These medications are primarily used to lower LDL cholesterol levels. Other treatments, such as ANGPTL3 inhibitors, decrease the residual risk of heart disease in patients with high LDL cholesterol levels. However, even with these therapies, less than 35% of Americans with high LDL cholesterol levels reach their target levels recommended by guidelines. CVD events still occur even when LDL cholesterol levels meet clinical goals. Many patients also struggle to continue taking their medications long-term, with less than 50% of patients taking their LDL-lowering medicines 2 years after a CVD event. Additionally, 5 to 10% of patients cannot tolerate high doses of statins, primarily due to muscle aches.

AX-1412 for Cardiovascular Disease targeting B4GALT1

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AX-1412 represents a potential targeted approach to RNA editing of B4GALT1 that leads to a loss of function is a promising strategy for protecting against cardiovascular disease by simultaneously lowering levels of LDL-c and fibrinogen. Recent gene-based analysis has shown that rare protein loss-of-function variants and predicted deleterious missense variants in B4GALT1 are associated with a decreased risk of coronary artery disease. Additionally, a particular missense variant (p.Asn352Ser) in the beta-1,4-galactosyltransferase 1 B4GALT1 gene is prevalent in the Amish population and associated with lower levels of LDL-c and cardiovascular disease.

The beneficial effects of these genetic variations are due to the hypo-galactosylation of apolipoprotein B100 and fibrinogen, which are known to be independent drivers of an increased risk of cardiovascular disease, as well as immunoglobulin G and transferrin. However, it's important to note that studies have shown that B4GALT1 knockdown can lead to semi-lethality and severe developmental abnormalities in mice models and therefore we believe B4GALT1 inhibition is not a feasible therapeutic approach for this purpose.

Although there are several approaches to lowering the risks of cardiovascular disease, including reducing LDL-c and ApoB levels, reducing fibrinogen levels may offer additional benefits to patients with unmet medical needs in this large population. Fibrinogen reduction can be used either as a stand-alone therapy or an adjunct therapy to other treatments.

We are developing Axiomer targeted RNA EON AX-1412 to address CVD by editing B4GALT1. RNA editing to a loss of function variant of B4GALT1 can have positive effect on cardiovascular diseases risk factors by leading to hypo-galactosylation of apolipoprotein B100 and fibrinogen. Based on its mechanism of action, we believe that AX-1412 is a novel and unique approach to address CVD by lowering LDL-C and fibrinogen levels ultimately leading to a reduced residual risk in cardiovascular diseases.

We intend to advance AX-1412 targeting B4GALT1 to early clinical proof of concept stage, then would seek to partner this program.

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Our Earlier-Stage/Discovery Programs

We have multiple other early-stage research programs ongoing that target additional diseases with our Axiomer EON approach, including AX-1005 for undisclosed targets in CVD, AX-2911 for nonalcoholic steatohepatitis (NASH), AX-0601 for obesity and Type 2 diabetes, AX-9115 for rare metabolic condition, and AX-2402 for rare neurodegenerative conditions, as well as multiple other targets in our discovery pipeline.

Our Partnership Strategy

Our business strategy is to develop and ultimately commercialize a broad pipeline of RNA therapies based on our Axiomer RNA editing platform technology. We are initially focused on developing an internal pipeline based on liver-originating diseases, including Cholestatic Diseases and CVD, among others. We believe there is broad applicability of the platform beyond liver and as part of the strategy to advance Axiomer, we have entered into, and expect to enter into additional collaboration and licencing agreements as a means of obtaining funding and capabilities to advance programs based on Axiomer.

A global licensing and research collaboration with Eli Lilly and Company focuses on the discovery, development, and commercialization of potential new medicines for genetic disorders using our Axiomer RNA editing technology with a focus on central nervous system, or CNS, and peripheral nervous system, or PNS. The partnership, formed in 2021, initially focused on up to five targets. In December 2022, the partnership was expanded to up to ten targets, with an option for an additional five targets. Under the terms of the agreements, we received $125 million upfront from Lilly and would be paid an additional $50 million if Lilly exercises the option for five additional targets. We are also eligible to receive up to approximately $3.75 billion in milestones, as well as royalties on potential product sales.

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We believe the platform holds significant further potential for strategic transactions.

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Ophthalmology Assets

In August 2022, we made the decision to exclusively focus our strategy on the advancement of our Axiomer RNA editing technology and to partner our ophthalmology programs. The process to partner these programs is ongoing.

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Competition

The pharmaceutical industry is highly competitive and subject to rapid and significant technological change. Our potential competitors include large pharmaceutical, biotechnology, specialty pharmaceutical, and generic drug companies, academic institutions, government agencies and research institutions. Key competitive factors affecting the commercial success of our product candidates are likely to be efficacy, safety and tolerability profile, delivery, reliability, convenience of dosing, patient recruitment for clinical studies, price and reimbursement. Many of our existing or potential competitors have substantially greater financial, technical, and human resources than we do and significantly greater experience in the discovery and development of product candidates, obtaining FDA, EMA and other regulatory approvals of products and the commercialization of those products. Mergers and acquisitions in the pharmaceutical and biotechnology industries may result in even more resources being concentrated among a small number of our competitors. Accordingly, our competitors may be more successful than we may be in obtaining FDA or EMA approval for therapies and achieving widespread market acceptance. Our competitors’ products may be more effective, or more effectively marketed and sold, than any product we may commercialize and may render our therapies obsolete or non-competitive before we can recover development and commercialization expenses.

Our competitors are working on similar technologies in the field of RNA editing, but also in the field of gene editing and gene therapy as well as other types of therapies, such as small molecules, protein replacement or antibodies.

Human Capital Resources

We believe in passion and commitment and have built a strong team of ProQRians from all walks of life and approximately 35 different nationalities, who are up to the challenge and committed to make a difference for the patients we serve. We actively create a caring atmosphere, in which we love to work and maintain productive and happy lives. At ProQR we foster empowerment, self-development, creativity, and a sense of community.

As an employer, we are a true believer in the value of a workforce in which people from diverse backgrounds are encouraged to develop themselves both personally and professionally. This is reflected in our equal gender balanced leadership team and broader workforce. We believe that happy and energized people, working well together in an environment in which they thrive, will do phenomenal and awesome things.

We are committed to ensure that no employee, candidate, or job applicant receives less favorable treatment on the grounds of race, age, disability, pregnancy, religion, gender identity and expression, sexual orientation, marriage or civil partnership status. At ProQR we want to create an inclusive culture where everyone can be valued for who they are and in which individual differences and the contributions in all forms are recognized and valued.

Animal Welfare

It is required by regulatory authorities to demonstrate the safety and, if possible, efficacy of a new drug in animals before it can be tested in humans. The welfare of animals in our preclinical studies is of great importance to us for reasons of ethics, quality, reliability, and applicability of scientific studies. To assure high quality (scientific) research, animal welfare is essential. By actively pursuing the 3R principles (Reduce, Refine and Replace), ProQR is committed to reduce the number of animals needed, minimize discomfort and pain of animals used, and use alternatives to animal research whenever possible.

Animal experiments will be performed only if there are no alternatives such as performing in silico, in vitro or ex vivo studies. Study designs will be evaluated with the aim to identify opportunities to reduce the number of animals needed to achieve the objectives of the study. By conducting small pilot (tolerability) studies and by using innovative new technologies and modeling approaches, we further pursues the ambition to reduce, refine and replace animal studies.

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Approval by the (institutional or national) animal care and use committees is required prior the execution of in vivo studies.

External collaborators contracted for the execution of our in vivo preclinical studies, also known as contract research organizations (CROs), are selected based on their expertise, quality and accreditations for laboratory animal care and

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welfare. CRO facilities are audited by us prior to contracting to ensure that the housing, husbandry and welfare of animals complies with the highest international standards. Personnel responsible for housing, husbandry and the care of animals must have received adequate and relevant documented education.

Manufacturing and Supply

ProQR does not own or operate GxP manufacturing facilities to produce clinical or commercial drug product. Historically manufacture of drug substance and drug product for clinical use was outsourced to approved vendors under service agreements.

Currently, manufacture of small scale non GxP drug substance and drug product batches to support the discovery and initial pre-clinical phase of the Axiomer platform are manufactured in our in-house laboratories. As the portfolio progresses, larger scale batches and those intended for clinical use will be manufactured at approved vendors under phase appropriate service agreements.

Our vendor management strategy will ensure that we have sufficient capacity to meet the demands of the portfolio now and in the future. The contract manufacturing organizations selected to manufacture our product candidates under cGMP conditions are assessed and audited to ensure that they meet the extensive regulations imposed eg technical expertise, facility and equipment management, documentation, data integrity, manufacturing processes and controls, personnel, quality control and quality assurance.

Intellectual Property

We strive to protect our technology platforms and our product candidates through a variety of approaches, including obtaining and maintaining patent and trade secret protection for our current and future technology platforms, our product candidates as well as their methods of use and processes for their manufacture, and any other inventions or discoveries that are commercially important to our business. We seek to obtain domestic and international patent protection and endeavor to promptly file patent applications or in-license patent rights relating to new, commercially valuable inventions to expand our intellectual property portfolio.

Our commercial success will depend in part upon obtaining and maintaining patent and trade secret protection for our current and future technology platforms and product candidates, as well as successfully defending our patent rights against third-party challenges. Our ability to prevent or stop third parties from making, using, selling, offering to sell or importing our product candidates will depend in part upon whether we have valid and enforceable patent rights that cover the activities of third parties.

We cannot be sure that patents will be granted with respect to any of our own or our in-licensed pending patent applications or with respect to any patents applications we may own or in-license in the future, nor can we be sure that any of our own or in-licensed patents or any patents we may own or license in the future will be useful in protecting our technology. Please see “Risk Factors—Risks Related to Our Intellectual Property” for additional information on the risks associated with our intellectual property strategy and portfolio.

Patent Rights

We have been building and will continue to build our patent portfolio. Where possible, we pursue or plan to pursue multi-tiered patent protection for our technology platforms and our product candidates as well as their manufacture, formulation and use. In addition to the United States, we file, and plan to file, patent applications in various countries and regions where we think such filings are likely to be cost effective.

The term of individual patents depends upon the legal term of the patents in the countries in which they are obtained. In most countries in which we file or plan to file, the patent term is 20 years from the earliest date of filing of a non-provisional patent application. In the United States, a patent’s term may be lengthened by patent term adjustment, which compensates a patentee for administrative delays by the U.S. PTO in granting a patent. However, the term of a United States patent may be shortened if a patent is terminally disclaimed by its owner over another patent. In addition, depending upon the circumstances, certain United States patents may be eligible for a patent term extension which

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compensates a patentee for delays in granting marketing approval for a patented active ingredient or use of an active ingredient. In Europe, a similar mechanism is available, such that patents may be eligible for a supplementary protection certificate to compensate for the time lost in obtaining marketing authorization for the active ingredient.

Patent Rights Relating to Our Axiomer Program

ProQR’s Axiomer RNA editing technology platform uses EONs to recruit and direct endogenously expressed ADARs to edit an A to an I in the RNA, which is then translated as a G, allowing highly specific editing. Since 2014, when the first inventions were conceived at ProQR, we have been filing patent applications for intellectual property rights related to our Axiomer® platform. Many of these claim EONs with specific features that allow them to guide recruitment of endogenous ADAR for the purpose of therapeutic RNA editing, without the need of ADAR overexpression or artificial ADAR recruitment systems. Further to that, we have grown a strong intellectual property position for EONs that can bring about RNA editing in RNA to yield a gain-of-function alteration or a loss-of-function alteration in a wide variety of therapeutic areas. We rely, and continue to rely, on intellectual property rights that are fully owned by us, or that have been co-filed with our research collaborators.

With regard to our Axiomer program, we filed the following international patent applications from 2015 to 2021, several of which were continued in national and regional patent applications after the respective international phases.

PCT/EP2015/080347 – Granted in Canada (CA 2,968,336), China (ZL 201580069286.1), Europe (EP 3234134 B1), Israel (IL 252386), Japan (JP 6718872), New Zealand (NZ 732182), Russia (RU 2711506), South Africa (ZA 2017/03464) and the U.S. (US 10,676,737). Pending in Australia, Brazil, India, and the U.S. (divisional application). The term of any patents resulting from these applications would be expected to extend to at least 2035.

PCT/EP2017/065467 – Granted in Japan (JP 7074345), South Korea (KR 10-2418185) and the U.S. (US 10,988,763). Pending in Australia, Canada, China, Eurasia, Europe, Israel, New Zealand, and the U.S. (continuation application). The term of any patents resulting from these applications would be expected to extend to at least between 2037.

PCT/EP2017/071912 – Granted in Europe (EP 3507366 B1), Japan (JP 2019-511856), New Zealand (NZ 751483), South Korea (KR 10-2501980), South Africa (ZA 2019/01016) and the U.S. (US 10,941,402). Pending in Australia, Canada, China, India, and the U.S. (continuation applications). The term of any patents resulting from these applications would be expected to extend to at least between 2037.

PCT/EP2018/051202 – Granted in the U.S. (US 11,274,300). Pending in Europe. The term of a patent resulting from this application would be expected to extend to at least between 2038.

PCT/EP2019/062163 – Pending in Australia, Canada, Europe, Japan, New Zealand, and the U.S. The term of any patents resulting from these applications, if issued, would be expected to extend to at least 2039.

PCT/EP2020/053283 – Pending in Australia, Canada, Europe, Israel, New Zealand, and the U.S. The term of any patents resulting from these applications, if issued, would be expected to extend to at least 2040.

PCT/EP2020/059369 – Pending in Australia, Canada, China, Europe, Israel, Japan, New Zealand, and the U.S. The term of any patents resulting from these applications, if issued, would be expected to extend to at least 2040.

PCT/EP2020/060291 – Pending in Australia, Canada, Europe, Israel, New Zealand, and the U.S. The term of any patents resulting from these applications, if issued, would be expected to extend to at least 2040.

PCT/US2020/037580 – Granted in South Africa (ZA 2021/09497). Pending in Australia, Canada, China, Europe, Israel, India, Japan, New Zealand, and the U.S. We filed this application together with The Regents of the University of California as a co-applicant. In the Axiomer program we are working together with Dr. Peter Beal of the University of California, Davis, CA, USA. The term of any patents resulting from these applications, if issued, would be expected to extend to at least 2040.

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PCT/EP2021/070535 – Pending in Australia, Canada, Europe, Japan, and the U.S. The term of any patents resulting from these applications, if issued, would be expected to extend to at least 2041.

Patent Rights Relating to Our TRIDENT Program

With regard to our TRIDENT program, we filed an international patent application (PCT/US2019/024282) in 2019 directed to antisense oligonucleotides that are applicable for nucleotide-specific pseudouridylation. A patent was granted in South Africa (ZA 2020/05217) and applications are currently pending in Australia, Canada, China, Europe, Israel, India, Japan, New Zealand, and the U.S. In the TRIDENT program we are working together with Prof. Yi-Tao Yu at the University of Rochester, NY, USA. The term of any patents resulting from these applications would be expected to extend to at least 2039.

Trade Secrets

In addition to patent protection, we rely on trade secrets and know-how to develop and maintain our competitive position. Trade secrets and know-how can be difficult to protect. Nevertheless, we seek to protect our trade secrets and know-how via, among other things, confidentiality and invention assignment agreements with our employees and consultants. We also seek to preserve the confidentiality of our trade secrets and know-how by implementing and maintaining security of our premises and information and limiting access to our trade secrets and know-how.

License Agreements

In February 2019, we entered into an agreement with the University of Rochester, New York, which gives us a world-wide, exclusive, royalty-bearing, sublicensable license in the field of antisense oligonucleotides for use in nucleotide specific RNA editing through pseudouridylation, under certain patent rights of University of Rochester. This license agreement contains certain diligence obligations for the Company coupled to milestone payments and complements the Company’s intellectual property relating to the Trident program. The royalties payable under this license agreement are in the low single digits.

Regulatory Matters

Government Regulation and Product Approval

Government authorities in the United States at the federal, state and local level, and in other countries, extensively regulate, among other things, the research, development, testing, manufacture, quality control, approval, labeling, packaging, storage, record-keeping, promotion, advertising, distribution, marketing, export and import of products such as those we are developing.

U.S. Drug Development Process

In the United States, the FDA regulates drugs under the Federal Food, Drug, and Cosmetic Act, or FDCA, and its implementing regulations and other federal, state and local statutes and regulations. The process of obtaining regulatory approvals and compliance with appropriate federal, state, local and foreign statutes and regulations require the expenditure of substantial time and financial resources. Failure to comply with the applicable U.S. requirements at any time during the product development process, approval process, or after approval, may subject an applicant to administrative or judicial sanctions. These sanctions could include the FDA’s refusal to approve pending applications, withdrawal of an approval, a clinical hold, untitled or warning letters, product recalls, product seizures, total or partial suspension of production or distribution, injunctions, fines, refusals of government contracts, restitution, disgorgement or civil or criminal penalties. The process required by the FDA before a drug may be marketed in the United States generally involves the following:

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The testing and approval process require substantial time, effort and financial resources and we cannot be certain that any approvals for our product candidates will be granted on a timely basis, if at all.

Once a pharmaceutical product candidate is identified for development, it enters the preclinical testing stage. Preclinical tests include laboratory evaluations of product chemistry, toxicity, formulation and stability, as well as animal studies. An IND sponsor must submit the results of the preclinical tests, together with manufacturing information, analytical data and any available clinical data or literature, to the FDA as part of the IND. The sponsor must also include a protocol detailing, among other things, the objectives of the initial clinical trial, the parameters to be used in monitoring safety and the effectiveness criteria to be evaluated if the initial clinical trial lends itself to an efficacy evaluation. Some preclinical testing may continue even after the IND is submitted. The IND automatically becomes effective 30 days after receipt by the FDA, unless the FDA raises concerns or questions related to a proposed clinical trial and places the trial on a clinical hold within that 30-day time period. In such a case, the IND sponsor and the FDA must resolve any outstanding concerns before the clinical trial can begin. Clinical holds also may be imposed by the FDA at any time before or during clinical trials due to safety concerns or non-compliance and may be imposed on all drug products within a certain class of drugs. The FDA also can impose partial clinical holds, for example, prohibiting the initiation of clinical trials of a certain duration or for a certain dose.

All clinical trials must be conducted under the supervision of one or more qualified investigators in accordance with GCP regulations. These regulations include the requirement that all research subjects provide informed consent in writing before their participation in any clinical trial. Further, an IRB must review and approve the plan for any clinical trial before it commences at any institution, and the IRB must conduct continuing review and reauthorize the trial at least annually. An IRB considers, among other things, whether the risks to individuals participating in the clinical trial are minimized and are reasonable in relation to anticipated benefits. The IRB also approves the information regarding the clinical trial and the consent form that must be provided to each clinical trial subject or his or her legal representative and must monitor the clinical trial until completed.

Each new clinical protocol and any amendments to the protocol must be submitted for FDA review, and to the IRBs for approval. Protocols detail, among other things, the objectives of the clinical trial, dosing procedures, subject selection and exclusion criteria, the parameters to assess efficacy and the parameters to be used to monitor subject safety.

Human clinical trials are typically conducted in three sequential phases that may overlap or be combined:

Phase 1. The product is initially introduced into a small number of healthy human subjects or patients and tested for safety, dosage tolerance, absorption, metabolism, distribution and excretion and, if possible, to gain early evidence on effectiveness. In the case of some products for severe or life-threatening diseases, especially

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when the product is suspected or known to be unavoidably toxic, the initial human testing may be conducted in patients.

Phase 2. Involves clinical trials in a limited patient population to identify possible adverse effects and safety risks, to preliminarily evaluate the efficacy of the product for specific targeted diseases and to determine dosage tolerance and optimal dosage and schedule.

Phase 3. Clinical trials are undertaken to further evaluate dosage, clinical efficacy and safety in an expanded patient population. These clinical trials are intended to establish the overall risk/benefit relationship of the product and provide an adequate basis for product labeling.

Post-approval trials, sometimes referred to as Phase 4 clinical trials, may be conducted after initial marketing approval. These trials are used to gain additional experience from the treatment of patients in the intended therapeutic indication. In certain instances, the FDA may mandate the performance of Phase 4 clinical trials as a condition of approval of an NDA.

Progress reports detailing the results of the clinical trials must be submitted at least annually to the FDA. Within 15 calendar days after the sponsor determines that the information qualifies for reporting, written IND safety reports must be submitted to the FDA and the investigators for serious and unexpected suspected adverse events, any clinically important increase in the rate of a serious suspected adverse reaction over that listed in the protocol or investigator's brochure, or any findings from other studies or animal or in vitro testing that suggest a significant risk in humans exposed to the product drug. The sponsor also must notify the FDA of any unexpected fatal or life-threatening suspected adverse reaction within seven calendar days after the sponsor’s initial receipt of the information. Phase 1, Phase 2 and Phase 3 testing may not be completed successfully within any specified period, if at all. The FDA or the sponsor may suspend or terminate a clinical trial at any time on various grounds, including a finding that the research subjects or patients are being exposed to an unacceptable health risk. Similarly, an IRB can suspend or terminate approval of a clinical trial at its institution if the clinical trial is not being conducted in accordance with the IRB’s requirements or if the drug has been associated with unexpected serious harm to patients. Additionally, some clinical trials are overseen by an independent group of qualified experts organized by the clinical trial sponsor, known as a data safety monitoring board or committee. This group provides authorization for whether a trial may move forward at designated checkpoints based on access to certain data from the trial.

Concurrent with clinical trials, companies usually complete additional animal studies and must also develop additional information about the chemistry and physical characteristics of the product and finalize a process for manufacturing the product in commercial quantities in accordance with cGMP requirements. The manufacturing process must be capable of consistently producing quality batches of the product candidate and, among other things, the manufacturer must develop methods for testing the identity, strength, quality and purity of the final product. Additionally, appropriate packaging must be selected and tested, and stability studies must be conducted to demonstrate that the product candidate does not undergo unacceptable deterioration over its shelf life.

A drug being studied in clinical trials may be made available to individual patients in certain circumstances outside of clinical trials, known as expanded access or “compassionate use”. There is no requirement for a company to provide expanded access to its investigational product. However, if a company decides to make its investigational product available for expanded access, FDA reviews each request for expanded access and determines if treatment may proceed. Under the FDCA, a sponsor of one or more investigational products for the treatment of a serious disease or condition is required to make publicly available, such as by posting on its website, its policy on evaluating and responding to requests for individual patient access to such investigational drug. This requirement applies on the earlier of the first initiation of a Phase 2 or Phase 3 trial of the investigational drug, or as applicable, 15 days after the drug receives a designation as a breakthrough therapy, fast track product, or regenerative advanced therapy.

U.S. Review and Approval Processes

The results of product development, preclinical studies and clinical trials, along with descriptions of the manufacturing process, analytical tests conducted on the drug, proposed labeling and other relevant information, are submitted to the FDA as part of an NDA for a new drug, requesting approval to market the product. The submission of an NDA is subject

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to the payment of a substantial user fee; a waiver of such fee may be obtained under certain limited circumstances. For example, the agency will waive the application fee for the first human drug application that a small business or its affiliate submits for review. The holder of an approved NDA is also subject to an annual prescription drug product program fee.

The FDA reviews all NDAs submitted to ensure that they are sufficiently complete for substantive review before it accepts them for filing. The FDA may request additional information rather than accept an NDA for filing. In this event, the NDA must be re-submitted with the additional information. The re-submitted application also is subject to review before the FDA accepts it for filing. Once the submission is accepted for filing, the FDA begins an in-depth substantive review. The FDA reviews an NDA to determine, among other things, whether a product is safe and effective for its intended use and whether its manufacturing is cGMP-compliant to assure the product’s identity, strength, quality and purity. Before approving an NDA, the FDA typically will inspect the facility or facilities where the product is or will be manufactured. The FDA will not approve an application unless it determines that the manufacturing processes and facilities are in compliance with cGMP requirements and adequate to assure consistent production of the product within required specifications. The FDA may refer the NDA to an advisory committee for review, evaluation and recommendation as to whether the application should be approved and under what conditions. An advisory committee is a panel of experts, including clinicians and other scientific experts, who provide advice and recommendations when requested by the FDA. The FDA is not bound by the recommendation of an advisory committee, but it considers such recommendations when making decisions.

The approval process is lengthy and difficult, and the FDA may refuse to approve an NDA if the applicable regulatory criteria are not satisfied or may require additional clinical data or other data and information. Even if such data and information are submitted, the FDA may ultimately decide that the NDA does not satisfy the criteria for approval. Data obtained from clinical trials are not always conclusive and the FDA may interpret data differently than we interpret the same data. The FDA will issue a complete response letter if the agency decides not to approve the NDA in its present form. The complete response letter usually describes all of the specific deficiencies that the FDA identified in the NDA that must be satisfactorily addressed before it can be approved. The deficiencies identified may be minor, for example, requiring labeling changes, or major, for example, requiring additional clinical trials. Additionally, the complete response letter may include recommended actions that the applicant might take to place the application in a condition for approval. If a complete response letter is issued, the applicant may either resubmit the NDA, addressing all of the deficiencies identified in the letter, or withdraw the application or request an opportunity for a hearing.

If a product receives regulatory approval, the approval may be significantly limited to specific patients and dosages or the indications for use may otherwise be limited, which could restrict the commercial value of the product. Further, the FDA may require that certain contraindications, warnings or precautions be included in the product labeling. In addition, the FDA may require post-approval studies, including Phase 4 clinical trials, to further assess a drug’s safety and effectiveness after NDA approval and may require testing and surveillance programs to monitor the safety of approved products that have been commercialized. The FDA may require a Risk Evaluation and Mitigation Strategy, or REMS, program as a condition of approval, which could entail requirements for long-term patient follow-up, a medication guide, physician communication plans or additional elements to ensure safe use, such as restricted distribution methods, patient registries and other risk minimization tools.

Fast Track Designation and Accelerated Approval

The FDA has a Fast Track program that is intended to expedite or facilitate the process for reviewing new drugs that meet certain criteria. Specifically, new drugs are eligible for Fast Track designation if they are intended to treat a serious or life-threatening disease or condition for which there is an unmet medical need and demonstrate the potential to address unmet medical needs for the condition. Fast Track designation applies to the combination of the product and the specific indication for which it is being studied. The sponsor of a new drug may request the FDA to designate the drug as a Fast Track product concurrently with, or at any time after, submission of an IND, and the FDA must determine if the drug candidate qualifies for fast track designation within 60 days of receipt of the sponsor’s request. In addition to other benefits, such as the ability to engage in more frequent interactions with the FDA, the FDA may initiate review of sections of a Fast Track drug’s NDA before the application is complete. This rolling review is available if the applicant provides, and the FDA approves, a schedule for the submission of each portion of the NDA and the applicant pays applicable user fees. However, the FDA’s time period goal for reviewing an application does not begin until the last

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section of the NDA is submitted. Additionally, the Fast Track designation may be withdrawn by the FDA if the FDA believes that the designation is no longer supported by data emerging in the clinical trial process.

Under FDA’s accelerated approval regulations, the FDA may approve a drug for a serious or life-threatening illness that provides meaningful therapeutic benefit to patients over existing treatments based upon a surrogate endpoint that is reasonably likely to predict clinical benefit, or on a clinical endpoint that can be measured earlier than irreversible morbidity or mortality, that is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit, taking into account the severity, rarity, or prevalence of the condition and the availability or lack of alternative treatments. In clinical trials, a surrogate endpoint is a marker, such as a measurement of laboratory or clinical signs of a disease or condition that is thought to predict clinical benefit, but is not itself a measure of clinical benefit. Surrogate endpoints can often be measured more easily or more rapidly than clinical endpoints. A drug candidate approved on this basis is subject to rigorous post-marketing compliance requirements, including the completion of post-approval clinical trials sometimes referred to as Phase 4 trials to confirm the effect on the clinical endpoint. Further, under the Food and Drug Omnibus Reform Act of 2022, or FDORA, the FDA may require, as appropriate, that such trials be underway prior to approval or within a specific time period after the date of approval for a product granted accelerated approval. Under FDORA, the FDA has increased authority for expedited procedures to withdraw approval of a drug or indication approved under accelerated approval for failure to conduct required post-approval studies with diligence, or to confirm a clinical benefit during post-marketing studies. All promotional materials for drug candidates approved under accelerated regulations are subject to prior review by the FDA.

Breakthrough Designation

A drug product can be designated as a breakthrough therapy if it is intended to treat a serious or life-threatening disease or condition and preliminary clinical evidence indicates that it may demonstrate substantial improvement over available therapies on one or more clinically significant endpoints. A sponsor may request that a drug product be designated as a breakthrough therapy concurrently with, or at any time after, the submission of an IND, and the FDA must determine if the drug candidate qualifies for breakthrough therapy designation within 60 days of receipt of the sponsor’s request. If so designated, the FDA shall act to expedite the development and review of the product’s marketing application, including by meeting with the sponsor throughout the product’s development, providing timely advice to the sponsor to ensure that the development program to gather preclinical and clinical data is as efficient as practicable, involving senior managers and experienced review staff in a cross-disciplinary review, assigning a cross-disciplinary project lead for the FDA review team to facilitate an efficient review of the development program and to serve as a scientific liaison between the review team and the sponsor, and taking steps to ensure that the design of the clinical trials is as efficient as practicable.

Platform Technology Designation

Under FDORA, a platform technology incorporated within or utilized by a drug or biological product is eligible for designation as a designated platform technology if (1) the platform technology is incorporated in, or utilized by, a drug approved under an NDA or biologics license application, or BLA; (2) preliminary evidence submitted by the sponsor of the approved or licensed drug, or a sponsor that has been granted a right of reference to data submitted in the application for such drug, demonstrates that the platform technology has the potential to be incorporated in, or utilized by, more than one drug without an adverse effect on quality, manufacturing, or safety; and (3) data or information submitted by the applicable person indicates that incorporation or utilization of the platform technology has a reasonable likelihood to bring significant efficiencies to the drug development or manufacturing process and to the review process. A sponsor may request the FDA to designate a platform technology as a designated platform technology concurrently with, or at any time after, submission of an IND application for a drug that incorporates or utilizes the platform technology that is the subject of the request. If so designated, the FDA may expedite the development and review of any subsequent original NDA or BLA for a drug that uses or incorporates the platform technology. Designated platform technology status does not ensure that a drug will be developed more quickly or receive FDA approval. In addition, the FDA may revoke a designation if the FDA determines that a designated platform technology no longer meets the criteria for such designation.

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Priority Review

The FDA may grant an NDA a priority review designation, which sets the target date for FDA action on the application for a new molecular entity at six months after the FDA accepts the application for filing. Priority review is granted where there is evidence that the proposed product would be a significant improvement in the safety or effectiveness of the treatment, diagnosis, or prevention of a serious condition compared to available therapies. If criteria are not met for priority review, the application is subject to the standard FDA review period of ten months after FDA accepts the application for filing. Priority review designation does not change the scientific/medical standard for approval or the quality of evidence necessary to support approval.

Rare Pediatric Disease Priority Review Voucher

The FDA may grant rare pediatric disease designation for indications in the treatment or prevention of a rare disease or condition that affects fewer than 200,000 individuals in the United States and that is a serious or life-threatening disease that primarily affects individuals aged from birth to 18 years, including age groups often called neonates, infants, children and adolescents. Under the FDCA, a sponsor who receives approval of an NDA for a product that is for the prevention or treatment of a rare pediatric disease and meets certain additional criteria, may qualify for a rare pediatric disease priority review voucher, or PRV. A PRV can be redeemed to receive priority review under an expedited timeframe for a subsequent marketing application for a different product. A PRV may also be sold or transferred from the initial sponsor to another sponsor and may be further transferred any number of times before it is used. On December 27, 2020, the Rare Pediatric Disease Priority Review Voucher Program was extended. Under the current statutory sunset provisions, after September 30, 2024, FDA may only award a voucher for an approved rare pediatric disease product application if the sponsor has rare pediatric disease designation for the drug or biologic, and that designation was granted by September 30, 2024. After September 30, 2026, FDA may not award any rare pediatric disease priority review vouchers. It is possible the authority for FDA to award rare pediatric disease priority review vouchers will be further extended by Congress.

Post-Approval Requirements

Any products for which we receive FDA approval are subject to continuing regulation by the FDA, including, among other things, record-keeping requirements, reporting of adverse experiences with the product, providing the FDA with updated safety and efficacy information, product sampling and distribution requirements, complying with certain electronic records and signature requirements and complying with FDA promotion and advertising requirements. The FDA strictly regulates labeling, advertising, promotion and other types of information on products that are placed on the market. Products may be promoted only for the approved indications and in accordance with the provisions of the approved label. Further, manufacturers must continue to comply with cGMP requirements, which are extensive and require considerable time, resources and ongoing investment to ensure compliance. In addition, changes to the manufacturing process generally require prior FDA approval before being implemented and other types of changes to the approved product, such as adding new indications and additional labeling claims, are also subject to further FDA review and approval.

Manufacturers and other entities involved in the manufacturing and distribution of approved products are required to register their establishments with the FDA and certain state agencies, and are subject to periodic unannounced inspections by the FDA and certain state agencies for compliance with cGMP and other laws. The cGMP requirements apply to all stages of the manufacturing process, including the production, processing, sterilization, packaging, labeling, storage and shipment of the product. Manufacturers must establish validated systems to ensure that products meet specifications and regulatory standards, and test each product batch or lot prior to its release. Manufacturers and other parties involved in the drug supply chain for prescription drugs and biologics must also comply with product tracking and tracing requirements and for notifying the FDA of counterfeit, diverted, stole and intentionally adulterated products or products that are otherwise unfit for distribution in the United States.

The FDA may withdraw a product approval if compliance with regulatory requirements is not maintained or if problems occur after the product reaches the market. Later discovery of previously unknown problems with a product may result in restrictions on the product or even complete withdrawal of the product from the market. Further, the failure to maintain compliance with regulatory requirements may result in administrative or judicial actions, such as fines, untitled

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or warning letters, holds on clinical trials, product seizures, product detention or refusal to permit the import or export of products, refusal to approve pending applications or supplements, restrictions on marketing or manufacturing, injunctions or civil or criminal penalties.

From time to time, legislation is drafted, introduced and passed in Congress that could significantly change the statutory provisions governing the approval, manufacturing and marketing of products regulated by the FDA. In addition to new legislation, FDA regulations, guidance, and policies are often revised or reinterpreted by the agency in ways that may significantly affect our business and our product candidates. It is impossible to predict whether further legislative or FDA regulation or policy changes will be enacted or implemented and what the impact of such changes, if any, may be.

Patent Term Restoration and Marketing Exclusivity

Depending upon the timing, duration and specifics of FDA approval of the use of our product candidates, some of our U.S. patents may be eligible for limited patent term extension under the Drug Price Competition and Patent Term Restoration Act of 1984, commonly referred to as the Hatch-Waxman Amendments. The Hatch-Waxman Amendments permit a patent restoration term of up to five years as compensation for patent term lost during product development and the FDA regulatory review process. However, patent term restoration cannot extend the remaining term of a patent beyond a total of 14 years from the product’s approval date. The patent term restoration period is generally one-half the time between the effective date of an IND and the submission date of an NDA plus the time between the submission date of an NDA and the approval of that application, except that the review period is reduced by any time during which the applicant failed to exercise due diligence. Only one patent applicable to an approved drug is eligible for the extension and the application for the extension must be submitted prior to the expiration of the patent. The U.S. Patent and Trademark Office, in consultation with the FDA, reviews and approves the application for any patent term extension or restoration. In the future, we intend to apply for restorations of patent term for some of our currently owned or licensed patents to add patent life beyond their current expiration dates, depending on the expected length of the clinical trials and other factors involved in the filing of the relevant NDA; however, there can be no assurance that any such extension will be granted to us.

Market exclusivity provisions under the FDCA can also delay the submission or the approval of certain applications. The FDCA provides a five-year period of non-patent marketing exclusivity within the United States to the first applicant to gain approval of an NDA for a new chemical entity. A drug is a new chemical entity if the FDA has not previously approved any other new drug containing the same active moiety, which is the molecule or ion responsible for the action of the drug substance. During the exclusivity period, the FDA may not accept for review an abbreviated new drug application, or ANDA, or a 505(b)(2) NDA submitted by another company for another version of such drug where the applicant does not own or have a legal right of reference to all the data required for approval. However, an application may be submitted after four years if it contains a certification of patent invalidity or non-infringement. The FDCA also provides three years of marketing exclusivity for an NDA, 505(b)(2) NDA or supplement to an existing NDA if new clinical investigations, other than bioavailability studies, that were conducted or sponsored by the applicant are deemed by the FDA to be essential to the approval of the application, for example, new indications, dosages or strengths of an existing drug. This three-year exclusivity covers only the conditions of use associated with the new clinical investigations and does not prohibit the FDA from approving ANDAs for drugs containing the original active agent. Five-year and three-year exclusivity will not delay the submission or approval of a full NDA. However, an applicant submitting a full NDA would be required to conduct or obtain a right of reference to all of the preclinical studies and adequate and well-controlled clinical trials necessary to demonstrate safety and effectiveness.

Pediatric exclusivity is another type of exclusivity in the United States. Pediatric exclusivity, if granted, provides an additional six months to an existing exclusivity or statutory delay in approval resulting from a patent certification. This six-month exclusivity, which runs from the end of other exclusivity protection or patent delay, may be granted based on the voluntary completion of a pediatric clinical trial in accordance with an FDA-issued “Written Request” for such a clinical trial.

Orphan Drugs

Under the Orphan Drug Act, the FDA may grant orphan drug designation to drugs intended to treat a rare disease or condition—a disease or condition that affects fewer than 200,000 individuals in the United States, or more than 200,000

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individuals in the United States and for which there is no reasonable expectation that the cost of developing and making a drug in the United States for this type of disease or condition will be recovered from sales of the product. Orphan drug designation must be requested before submitting an NDA. After the FDA grants orphan drug designation, the generic identity of the drug and its potential orphan use are disclosed publicly by the FDA. Orphan drug designation does not convey any advantage in, or shorten the duration of, the regulatory review and approval process. The first NDA applicant to receive FDA approval for a particular active ingredient to treat a particular disease or condition with FDA orphan drug designation is entitled to a seven-year exclusive marketing period in the United States for that product, for that indication. During the seven-year exclusivity period, the FDA may not approve any other applications to market the same drug for the same disease or condition, except in limited circumstances, such as if the second applicant demonstrates the clinical superiority of its product to the product with orphan drug exclusivity through a demonstration of superior safety, superior efficacy, or a major contribution to patient care. Orphan drug exclusivity does not prevent FDA from approving a different drug for the same disease or condition, or the same drug for a different disease or condition. Among the other benefits of orphan drug designation are tax credits for certain research and a waiver of the NDA application user fee.

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Pediatric Information

Under the Pediatric Research Equity Act of 2003, as amended, NDAs or supplements to NDAs must contain data adequate to assess the safety and effectiveness of the drug for the claimed indications in all relevant pediatric subpopulations and to support dosing and administration for each pediatric subpopulation for which the drug is safe and effective. The FDCA requires that a sponsor who is planning to submit a marketing application for a drug product that includes a new active ingredient, new indication, new dosage form, new dosing regimen or new route of administration submit an initial Pediatric Study Plan, or PSP, within sixty days of an end-of-Phase 2 meeting or as may be agreed between the sponsor and the FDA. The initial PSP must include an outline of the pediatric study or studies that the sponsor plans to conduct, including study objectives and design, age groups, relevant endpoints and statistical approach, or a justification for not including such detailed information, and any request for a deferral of pediatric assessments or a full or partial waiver of the requirement to provide data from pediatric studies along with supporting information. The FDA may, on its own initiative or at the request of the applicant, grant deferrals for submission of data or full or partial waivers. The FDA and the sponsor must reach agreement on the PSP. A sponsor can submit amendments to an agreed-upon initial PSP at any time if changes to the pediatric plan need to be considered based on data collected from preclinical studies, early phase clinical trials, and/or other clinical development programs.

Disclosure of Clinical Trial Information

Sponsors of certain clinical trials of FDA-regulated products, including drugs, are required to register and disclose certain clinical trial information, which is publicly available at www.clinicaltrials.gov. Information related to the product, patient population, phase of investigation, trial sites and investigators, and other aspects of the clinical trial is then made public as part of the registration. Sponsors are also obligated to disclose the results of their clinical trials after completion. Disclosure of the results of these trials can be delayed until the new product or new indication being studied has been approved. Competitors may use this publicly available information to gain knowledge regarding the progress of development programs.

Pharmaceutical Coverage, Pricing and Reimbursement

Significant uncertainty exists as to the coverage and reimbursement status of any drug products for which we may obtain regulatory approval. In the United States, sales of any products for which we may receive regulatory approval for commercial sale will depend in part on the availability of coverage and reimbursement from third-party payors. Third-party payors include government authorities, managed care providers, private health insurers and other organizations. The process for determining whether a payor will provide coverage for a drug product may be separate from the process for setting the reimbursement rate that the payor will pay for the drug product. Third-party payors may limit coverage to specific drug products on an approved list, or formulary, which might not include all of the FDA-approved drugs for a particular indication. Moreover, a payor’s decision to provide coverage for a drug product does not imply that an adequate reimbursement rate will be approved. Adequate third-party reimbursement may not be available to enable us to maintain price levels sufficient to realize an appropriate return on our investment in product development.

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Third-party payors are increasingly challenging the price and examining the medical need and cost-effectiveness of medical products and services, in addition to their safety and efficacy. In order to obtain coverage and reimbursement for any product that might be approved for sale, we may need to conduct expensive pharmaco-economic studies in order to demonstrate the medical need and cost-effectiveness of any products, in addition to the costs required to obtain regulatory approvals. Our product candidates may not be considered medically necessary or cost-effective. If third-party payors do not consider a product to be cost-effective compared to other available therapies, they may not cover the product after approval as a benefit under their plans or, if they do, the level of payment may not be sufficient to allow a company to sell its products at a profit.

The U.S. government and state legislatures have shown significant interest in implementing cost containment programs to limit the growth of government-paid health care costs, including price controls, restrictions on reimbursement and requirements for substitution of generic products for branded prescription drugs. For example, the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act of 2010, collectively, the Affordable Care Act (ACA), contains provisions that may reduce the profitability of drug products, including, for example, increased rebates for drugs reimbursed by Medicaid programs, extension of Medicaid rebates to Medicaid managed care plans, mandatory discounts for certain Medicare Part D beneficiaries and annual fees based on pharmaceutical companies’ share of sales to federal health care programs. Adoption of government controls and measures, and tightening of restrictive policies in jurisdictions with existing controls and measures, could limit payments for pharmaceuticals.

The marketability of any products for which we receive regulatory approval for commercial sale may suffer if the government and third-party payors fail to provide adequate coverage and reimbursement. In addition, an increasing emphasis on cost containment measures in the United States has increased and we expect will continue to increase the pressure on pharmaceutical pricing. Coverage policies and third-party reimbursement rates may change at any time. Even if favorable coverage and reimbursement status is attained for one or more products for which we receive regulatory approval, less favorable coverage policies and reimbursement rates may be implemented in the future.

Other Healthcare Laws and Compliance Requirements

If we obtain regulatory approval of our products, we will be subject to various federal and state laws targeting fraud and abuse in the healthcare industry. These laws may impact, among other things, our proposed sales, marketing and education programs. In addition, we may be subject to patient privacy regulation by both the federal government and the states in which we conduct our business in the U.S. and applicable privacy legislation outside of the U.S., such as the GDPR in the European Union and the United Kingdom. The laws that may affect our ability to operate include:

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