Core Viewpoint - Disc Medicine, Inc. has completed enrollment in the Phase 3 APOLLO trial for bitopertin, which targets erythropoietic protoporphyria (EPP), expanding the study size to 183 participants due to high demand [1][7]. Group 1: Study Details - The APOLLO trial is a double-blind, placebo-controlled study involving patients aged 12 and above, with sites in the US, Canada, Europe, and Australia [2]. - Co-primary endpoints include average monthly total time in sunlight without pain and percent change in whole blood metal-free PPIX after 6 months of treatment [2]. - Results from the APOLLO study are expected in Q4 2026, with a complete response letter (CRL) to be submitted to the FDA, and a decision anticipated by mid-2027 [2][7]. Group 2: About Bitopertin - Bitopertin is an investigational, orally administered inhibitor of glycine transporter 1 (GlyT1), aimed at modulating heme biosynthesis and supporting erythropoiesis [3]. - It is being developed as a potential first disease-modifying therapy for erythropoietic porphyrias [3]. - The drug has undergone multiple clinical trials, including the Phase 2 BEACON and AURORA trials, and the ongoing Phase 3 APOLLO trial [3]. Group 3: Company Overview - Disc Medicine is focused on discovering, developing, and commercializing novel treatments for serious hematologic diseases, targeting heme biosynthesis and iron homeostasis [5]. - The company aims to build a portfolio of innovative therapeutic candidates to address a wide spectrum of hematologic diseases [5]. - Disc obtained global rights to bitopertin from Roche in May 2021 [4].

Core Viewpoint - Disc Medicine, Inc. announced that the FDA issued a Complete Response Letter (CRL) for the New Drug Application (NDA) for bitopertin, delaying its potential approval for treating erythropoietic protoporphyria (EPP) [1] Group 1: FDA Review and Approval Process - The FDA acknowledged that previous trials (AURORA and BEACON) provided sufficient evidence that bitopertin significantly lowers whole blood metal-free PPIX [2][6] - However, the FDA concluded that the trials did not demonstrate a clear association between the change in PPIX levels and clinical benefits related to sunlight exposure, necessitating further evidence from the ongoing APOLLO study for traditional approval [2][6] - The APOLLO study is expected to provide topline data in Q4 2026, which could serve as a basis for traditional approval [6] Group 2: Company Response and Future Plans - The company remains committed to delivering bitopertin to the EPP community and plans to pursue all avenues for FDA approval despite the CRL [3] - Disc Medicine is confident in the ongoing APOLLO trial, which has seen significant enthusiasm from patients and physicians, leading to early completion of trial enrollment in March 2026 [3] - Following the completion of the APOLLO study, the company plans to respond to the CRL and anticipates an updated FDA decision by mid-2027 [3] Group 3: Financial Position - As of December 31, 2025, Disc Medicine reported approximately $791 million in cash, cash equivalents, and marketable securities, providing a financial runway into 2029 [3]