Quince Therapeutics Begins Phase 3 EryDex Trial for Ataxia-Telangiectasia

Quince Therapeutics, Inc. (Nasdaq: QNCX), based in South San Francisco, has announced the commencement of its Phase 3 NEAT clinical trial. This trial will investigate the neurological effects of EryDex in patients with Ataxia-Telangiectasia (A-T), a rare pediatric disease. The trial proceeds under a Special Protocol Assessment (SPA) agreement with the U.S. Food and Drug Administration (FDA).

The company’s Chief Executive Officer and Chief Medical Officer, Dirk Thye, M.D., emphasized the significance of this milestone for Quince and the potential benefits it holds for individuals affected by A-T. "The initiation of our pivotal Phase 3 NEAT study is a major milestone for Quince, and an opportunity for patients living with the devastating effects of Ataxia-Telangiectasia to participate in research seeking to identify a beneficial therapeutic solution,” said Thye. Currently, there are no approved therapeutic treatments for this condition in any global market, and Quince aims to change that.

The Phase 3 NEAT clinical trial (IEDAT-04-2022/NCT06193200) is designed as an international, multi-center, randomized, double-blind, placebo-controlled study. Approximately 86 patients aged six to nine years old will be enrolled as the primary analysis population, with an additional 20 patients aged 10 years or older included. Participants will be randomly assigned to receive either EryDex or a placebo, with treatments administered every 21 to 30 days over six infusions. The primary efficacy endpoint will be evaluated using the change from baseline to the last visit in the rescored modified International Cooperative Ataxia Rating Scale (RmICARS).

Participants who complete the treatment period and study assessments, and who provide informed consent, will have the option to transition to an open label extension (OLE) study. Quince anticipates reporting the topline results of the Phase 3 NEAT study in the second half of 2025. If the results are positive, the company plans to submit a New Drug Application (NDA) in 2026.

Following the enrollment of the first patient, Quince will make a $5 million milestone payment to the former shareholders of EryDel, the company that originally developed EryDex. No further development-related milestones are owed to EryDel shareholders.

Ataxia-Telangiectasia (A-T) is an inherited condition characterized by neurodegeneration and immunodeficiency due to mutations in the ATM gene. Symptoms typically appear before the age of five, with affected children developing an altered gait and increased frequency of falls. As the disease progresses, patients often require wheelchair assistance by adolescence and suffer from repeated infections, pulmonary impairments, and malignancies. The median lifespan for those with A-T is between 25 to 30 years, with mortality often resulting from infections and malignancies. In the U.S., there are approximately 4,600 diagnosed patients, while in the U.K. and EU4 countries, the number is around 5,000. Currently, there are no approved therapies for A-T.

EryDex, the therapeutic being evaluated, consists of dexamethasone sodium phosphate (DSP) encapsulated within a patient’s own red blood cells. DSP is a corticosteroid known for its anti-inflammatory effects but also for its potential toxicity due to adrenal suppression. EryDex aims to provide the benefits of corticosteroids while minimizing the adverse effects typical of chronic corticosteroid use. Quince’s proprietary Autologous Intracellular Drug Encapsulation (AIDE) technology, a novel drug/device combination, facilitates the encapsulation of drugs into a patient’s red blood cells. This method may offer enhanced tolerability, better tissue distribution, reduced immunogenicity, and prolonged drug circulation.

Quince Therapeutics is committed to developing life-changing therapeutics for individuals with rare diseases. The company uses innovative approaches to harness a patient’s biology for drug delivery, aiming to bring new treatment options to markets where none currently exist.