• No safety concerns identified by independent data and safety monitoring board, which recommends continuation of study without any modifications

SOUTH SAN FRANCISCO, Calif. / Nov 10, 2025 / Business Wire / Quince Therapeutics, Inc. (Nasdaq: QNCX), a late-stage biotechnology company dedicated to unlocking the power of a patient’s own biology for the treatment of rare diseases, today announced the positive outcome of its pre-planned safety analysis conducted by an independent data and safety monitoring board (iDSMB) for the company’s ongoing pivotal Phase 3 NEAT (Neurological Effects of eDSP in Subjects with A-T; NCT06193200/IEDAT-04-2022) clinical trial of its lead asset, encapsulated dexamethasone sodium phosphate (eDSP), in patients with Ataxia-Telangiectasia (A-T). The iDSMB recommended that the study continue without any modifications.

Dirk Thye, M.D., Quince’s Chief Executive Officer and Chief Medical Officer, said, “The positive outcome from our recent iDSMB review of eDSP reaffirms our confidence in the favorable safety profile of eDSP to date. As we continue to advance eDSP as a potential first-to-market A-T treatment, we are pleased that no safety concerns have been identified as our pivotal Phase 3 NEAT study progresses. We remain on track to report topline results from the study in the first quarter of 2026.”

Quince’s pivotal Phase 3 NEAT study is an international, multicenter, randomized, double-blind, placebo-controlled clinical trial to evaluate the neurological effects of eDSP in patients with A-T. This study consists of two cohorts randomized (1:1) between eDSP or placebo and treatment includes six infusions scheduled once every 21 to 30 days. The primary efficacy endpoint will be measured by the change from baseline to last efficacy visit using the Rescored modified International Cooperative Ataxia Rating Scale (RmICARS) compared to placebo.

About eDSP

eDSP is comprised of dexamethasone sodium phosphate (DSP) encapsulated in a patient’s own red blood cells (autologous erythrocytes). DSP is a corticosteroid well known for its anti-inflammatory properties as well as its dose-limiting toxicity due to adrenal suppression. The eDSP System is designed to provide the efficacy of corticosteroids and to reduce or eliminate the significant adverse effects that accompany chronic use of corticosteroid treatment.

eDSP leverages Quince’s proprietary Autologous Intracellular Drug Encapsulation, or AIDE, technology platform, which is a novel drug/device combination that uses an automated process designed to encapsulate a drug into the patient’s own red blood cells. Red blood cells have several characteristics that make them a potentially effective vehicle for drug delivery, including potentially better tolerability, enhanced tissue distribution, reduced immunogenicity, and prolongation of circulating half-life. Quince’s AIDE technology is designed to harness these benefits to allow for the chronic administration of drugs that have limitations due to toxicity, poor biodistribution, suboptimal pharmacokinetics, or immune response.

About Quince Therapeutics

Quince Therapeutics, Inc. (Nasdaq: QNCX) is a late-stage biotechnology company dedicated to unlocking the power of a patient’s own biology for the treatment of rare diseases. For more information on the company and its latest news, visit www.quincetx.com and follow Quince on social media platforms LinkedIn, Facebook, X, and YouTube.

Forward-looking Statements

Statements in this news release contain “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995 as contained in Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, which are subject to the “safe harbor” created by those sections. All statements, other than statements of historical facts, may be forward-looking statements. Forward-looking statements contained in this news release may be identified by the use of words such as “believe,” “may,” “should,” “expect,” “anticipate,” “plan,” “believe,” “estimated,” “potential,” “intend,” “will,” “can,” “seek,” or other similar words. Examples of forward-looking statements include, among others, statements relating to the results of clinical trials and related data; current and future clinical development of eDSP, including for the potential treatment of Ataxia-Telangiectasia (A-T); the strategic development path for eDSP; and the potential benefits of eDSP and the company’s market opportunity. Forward-looking statements are based on Quince’s current expectations and are subject to inherent uncertainties, risks, and assumptions that are difficult to predict and could cause actual results to differ materially from what the company expects. Further, certain forward-looking statements are based on assumptions as to future events that may not prove to be accurate. Factors that could cause actual results to differ include, but are not limited to, the risks and uncertainties described in the section titled “Risk Factors” in the company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (SEC) on March 24, 2025, Quarterly Report on Form 10-Q filed with the SEC on August 11, 2025, and other reports as filed with the SEC. Forward-looking statements contained in this news release are made as of this date, and Quince undertakes no duty to update such information except as required under applicable law.