The U.S. Food and Drug Administration (FDA) has issued a complete response letter to Disc Medicine, denying the company’s request for accelerated approval of bitopertin. The drug is designed to treat erythropoietic protoporphyria (EPP), a rare metabolic disorder that causes severe sensitivity to sunlight. According to the agency, the current data package was insufficient for an expedited path, though the FDA indicated that the company's ongoing Phase 3 study could support a traditional approval.

Shifting to a Traditional Regulatory Path

Disc Medicine expects to report topline data from its pivotal Phase 3 trial in the fourth quarter of 2024. If the results are favorable, the company plans to submit a formal response to the FDA’s letter. Based on this updated strategy, management anticipates a final regulatory ruling by mid-2027. Bitopertin aims to be a disease-modifying therapy for EPP patients, who currently face significant lifestyle restrictions due to their condition.

Chief Executive John Quisel acknowledged the setback but reiterated the firm’s commitment to the program, stating that the company is pursuing all available avenues for approval. The market response was immediate, with Disc Medicine shares falling 29% to $51.19 following the news. Analysts suggest the delay to 2027 creates a significant gap in the company’s near-term commercialization timeline.