Anticipated Upcoming Events

• AX-0810 targeting NTCP for Cholestatic diseases

  • Q2 2025 Clinical Trial Application (CTA) submission

  • Q4 2025 first clinical target engagement and biomarker data in healthy volunteers

• AX-2402 targeting MECP2 (R270X) for Rett Syndrome

  • 2025 clinical candidate selection

  • 2026 clinical trial initiation and topline data readout

• AX-2911 targeting PNPLA3 for MASH

  • 2025 clinical candidate selection

  • 2026 clinical trial initiation and topline data readout

• AX-1412 targeting B4GALT1 for Cardiovascular diseases

  • mid-2025 update on optimization for GalNAc delivery

• Continue to execute on partnership with Eli Lilly and Company (Lilly), with potential data updates, milestone income from the existing partnership, and an option to exercise for an additional five targets for expansion to a total of 15 targets, which would result in a $50 million opt-in payment to ProQR.

• ProQR may selectively form new partnerships, which could include multi-target discovery alliances, or product alliances on specific programs.

Financial Highlights

At March 31, 2025, ProQR held cash and cash equivalents of € 132.4 million, compared to € 149.4 million cash and cash equivalents at December 31, 2024. Net cash used in operating activities during the three-month period ended March 31, 2025 was € 15.8 million, compared to € 15.1 million for the same period last year. During the first quarter of 2025, the Company achieved a milestone in the collaboration agreement with Eli Lilly earning $1.0 million (€ 918,000).

Research and development (R&D) costs were € 12.3 million for the quarter ended March 31, 2025 compared to € 9.3 million for the same period last year.

General and administrative costs were € 3.2 million for the quarter ended March 31, 2025 compared to € 3.5 million for the same period last year.

Net loss for the three-month period ended March 31, 2025 was € 10.1 million, or € 0.10 per diluted share, compared to € 7.7 million, or € 0.09 per diluted share, for the same period last year. For further financial information for the period ended March 31, 2025, please refer to the Q1 financial report filing available on our website, www.proqr.com under Financials and Filings.

About Axiomer^™

ProQR is pioneering a next-generation RNA base editing technology called Axiomer^™, which could potentially yield a new class of medicines for diverse types of diseases. Axiomer^™ “Editing Oligonucleotides”, or EONs, 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) – correcting an RNA with a disease-causing mutation back to a normal (wild type) RNA, modulating protein expression, or altering a protein so that it will have a new function that helps prevent or treat disease.

About ProQR

ProQR Therapeutics is dedicated to changing lives through the creation of transformative RNA therapies. ProQR is pioneering a next-generation RNA technology called Axiomer^™, which uses a cell’s own editing machinery called ADAR to make specific single nucleotide edits in RNA to reverse a mutation or modulate protein expression and could potentially yield a new class of medicines for both rare and prevalent diseases with unmet need. Based on our unique proprietary RNA repair platform technologies we are growing our pipeline with patients and loved ones in mind.

Learn more about ProQR at www.proqr.com.

Forward Looking Statements

This press release contains forward-looking statements. All statements other than statements of historical fact are forward-looking statements, which are often indicated by terms such as “continue,” "anticipate," "believe," "could," "estimate," "expect," "goal," "intend," "look forward to", "may," "plan," "potential," "predict," "project," "should," "will," "would" and similar expressions. Such forward-looking statements include, but are not limited to, statements regarding our business, technology, strategy, preclinical and clinical model data, our initial pipeline targets and the upcoming strategic priorities and milestones related thereto, the responsibilities, potential strengths and capabilities of our new leadership appointments, the continued advancement of our lead development pipeline programs, including ongoing and planned clinical trials, the anticipated timing of initial clinical data readouts across multiple programs in 2025 and 2026, and the filing of a CTA application for our lead program, AX-0810, in Q2 2025, our Axiomer^™ platform, including the continued development and advancement of our Axiomer platform, the therapeutic potential of our Axiomer RNA editing oligonucleotides and product candidates, the timing, progress and results of our preclinical studies and other development activities, including the release of data related thereto, our patent estate, including our anticipated strength and our continued investment in it, as well as the timing of our clinical development, the potential of our technologies and product candidates, the collaboration with Lilly and the intended benefits thereof, including timing for data updates, potential milestones, exercise of an option to expand targets and the receipt of an opt-in payment, our ability to selectively form new partnerships and enter into future collaborations, and our financial position and cash-runway. Forward-looking statements are based on management's beliefs and assumptions and on information available to management only as of the date of this press release. Our actual results could differ materially from those expressed or implied by these forward-looking statements for many reasons, including, without limitation, the risks, uncertainties and other factors in our filings made with the Securities and Exchange Commission, including certain sections of our most recent annual report filed on Form 20-F. These risks and uncertainties include, among others, the cost, timing and results of preclinical studies and clinical trials and other development activities by us and our collaborative partners whose operations and activities may be slowed or halted shortage and pressure on supply and logistics on the global market, economic sanctions and international tariffs; the likelihood of our preclinical and clinical programs being initiated and executed on timelines provided and reliance on our contract research organizations and predictability of timely enrollment of subjects and patients to advance our clinical trials and maintain their own operations; our reliance on contract manufacturers to supply materials for research and development and the risk of supply interruption from a contract manufacturer; the potential for future data to alter initial and preliminary results of early-stage clinical trials; the unpredictability of the duration and results of the regulatory review of applications or clearances that are necessary to initiate and continue to advance and progress our clinical programs; the ability to secure, maintain and realize the intended benefits of collaborations with partners, including the collaboration with Lilly; the possible impairment of, inability to obtain, and costs to obtain intellectual property rights; possible safety or efficacy concerns that could emerge as new data are generated in research and development; general business, operational, financial and accounting risks, and risks related to litigation and disputes with third parties; and risks related to macroeconomic conditions and market volatility resulting from global economic developments, geopolitical events and conflicts, high inflation, rising interest rates, tariffs and potential for significant changes in U.S. policies and regulatory environment. Given these risks, uncertainties and other factors, you should not place undue reliance on these forward-looking statements, and we assume no obligation to update these forward-looking statements, even if new information becomes available in the future, except as required by law.

ProQR Therapeutics N.V.

Investor and media contact:
Sarah Kiely
ProQR Therapeutics N.V.
T: +1 617 599 6228
skiely@proqr.com
or
Investor contact:
Peter Kelleher
LifeSci Advisors
T: +1 617 430 7579
pkelleher@lifesciadvisors.com

Financial Tables

PROQR THERAPEUTICS N.V.
Unaudited Condensed Consolidated Statement of Financial Position

PROQR THERAPEUTICS N.V.
Unaudited Condensed Consolidated Statement of Profit or Loss and Other Comprehensive Income
(€ in thousands, except share and per share data)

1. For these periods the potential exercise of share options is not included in the diluted earnings per share as the Company was loss-making. Due to the anti-dilutive nature of the outstanding options, basic and diluted earnings per share are equal.
   
   

PROQR THERAPEUTICS N.V.
Unaudited Condensed Consolidated Statement of Changes in Equity

PROQR THERAPEUTICS N.V.
Unaudited Condensed Consolidated Statement of Cash Flows