Disc Medicine, Inc. (NASDAQ: IRON) saw robust patient demand for its lead drug candidate, bitopertin, with its pivotal APOLLO study enrolling 183 patients suffering from erythropoietic protoporphyria (EPP), a rare genetic blood disorder. The enrollment figure surpassed the clinical-stage biotechnology company’s original goal of 150 patients, signaling strong interest from physicians and patients for the small molecule therapy in a disease with limited treatment options.
“The study’s enrollment pace reflected tremendous demand and enthusiasm in both the United States and Europe,” John Quisel, Chief Executive Officer of Disc Medicine, said at an H.C. Wainwright event. Quisel noted that U.S. enrollment was halted early, while European sites opened in November and quickly filled the remaining slots, with the company allowing additional patients to join due to high interest.
The company expects to report data from the confirmatory APOLLO study in the fourth quarter of this year. This data is critical for Disc’s plan to resubmit its New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA). The agency previously issued a Complete Response Letter (CRL) for an accelerated approval application, questioning the correlation between protoporphyrin IX (PPIX) levels, a biomarker, and clinical symptoms. The APOLLO study is designed to provide the direct evidence of clinical benefit the FDA requires for a traditional approval.
A successful data readout would set up a six-month review period following a resubmission, putting Disc on a path for a potential U.S. approval by mid-2026. The company’s clinical experience suggests the EPP patient pool may be larger than the 3,000 to 6,000 patients traditionally estimated, with claims data pointing to a core group of 6,000 patients and a potential U.S. population closer to 20,000. The trial also includes adolescent patients, which could allow Disc to seek an initial label for patients as young as 12.
Beyond bitopertin, Disc Medicine is advancing a pipeline of hematology-focused drug candidates. The company is developing DISC-0974 for myelofibrosis-associated anemia, with new data expected at upcoming medical meetings. Interim results showed responses in patients both with and without concurrent JAK inhibitor treatment, a standard of care for myelofibrosis, suggesting it could address a persistent unmet need for anemia in this population.
Disc is also positioning DISC-3405, a monoclonal antibody, as an iron-restriction therapy for polycythemia vera (PV). This program aims to compete with therapies like rusfertide by offering a less frequent dosing schedule. The company is also initiating studies for DISC-3405 in sickle cell disease, exploring a novel drug-based approach to iron restriction, a concept currently being tested through therapeutic phlebotomy.
This article is for informational purposes only and does not constitute investment advice.
