Disc Medicine, Inc. (NASDAQ: IRON) recently announced that the U.S. Food and Drug Administration (FDA) has issued a complete response letter (CRL) for the new drug application (NDA) for bitopertin as a treatment for patients with erythropoietic protoporphyria (EPP). The FDA acknowledged that the Aurora and Beacon trials provided sufficient evidence that bitopertin significantly lowers whole blood metal-free protoporphyrin IX (PPIX), but indicated a need to see the results of the ongoing phase 3 Apollo study before making a decision.
The ongoing phase 3 Apollo study, with topline data anticipated in Q4 2026, has the potential to serve as the basis for traditional approval. Disc believes that the issue raised is readily addressable, given the Apollo study is already well underway with significant patient and physician enthusiasm, allowing the company to complete trial enrollment in March 2026, several months earlier than expected.
As of December 31, 2025, Disc Medicine had approximately $791 million in unaudited cash, cash equivalents, and marketable securities, with guidance to provide runway into 2029. The company plans to request a Type A meeting to review their approach with the FDA and expects to file a response to the CRL upon completion of the Apollo study, with an updated FDA decision anticipated by mid-2027.
Bitopertin is an investigational, clinical-stage, orally administered inhibitor of glycine transporter 1 (GlyT1) that is designed to modulate heme biosynthesis. It has been studied in multiple clinical trials in patients with EPP, including the Phase 2 open-label Beacon trial, the Phase 2 double-blind, placebo-controlled Aurora trial, an open-label extension Helios trial, and the confirmatory Phase 3 double-blind, placebo-controlled Apollo trial.
Disc Medicine will host a call for investors on Tuesday, February 17th to discuss this outcome. The company also plans to include a copy of the CRL in a Form 8-K to be filed with the Securities and Exchange Commission, which will be accessible on the company's investor relations website.
The market has reacted to these announcements by moving the company's shares -0.15% to a price of $70.93. For the full picture, make sure to review Disc Medicine's 8-K report.
