FDA Rejects Disc Medicine’s Porphyria Drug Bitopertin – First Under Makary’s Fast-Track Program

Washington – The Food and Drug Administration (FDA) rejected bitopertin, a treatment developed by Disc Medicine for porphyria, a rare blood disorder causing extreme sensitivity to sunlight. This decision marks the first time a drug has been reviewed under a new fast-track program initiated by FDA Commissioner Marty Makary.

A New Program, A First Rejection

The FDA previously approved a generic antibiotic through this same expedited review program in December. However, with bitopertin, the agency cited “uncertainties” regarding the link between a biomarker measured in clinical trials and actual clinical benefits for patients. The rejection led to a 31% drop in Disc Medicine’s share price, closing at $49 on Friday.

Did You Know? The FDA’s rejection of bitopertin occurred on Friday, February 13, 2026.

What’s Next for Disc Medicine?

Following the FDA’s decision, Disc Medicine could attempt to address the agency’s concerns and resubmit its application. It’s also possible the company will focus on the confirmatory trial design finalized with the FDA, which added a co-primary endpoint at the agency’s request. Analysts expect further evaluation of the company’s valuation given these developments.

Expert Insight: The FDA’s focus on the correlation between biomarkers and clinical benefit highlights the increasing scrutiny of drug approval pathways, particularly for rare diseases where traditional clinical trial endpoints may be challenging to define.

The FDA’s decision underscores the complexities of bringing new therapies to market, even under expedited review programs. The agency’s letter indicates a need for stronger evidence linking the drug’s impact on the biomarker to tangible improvements in patients’ health.

Frequently Asked Questions

What is porphyria?

Porphyria is a rare blood disorder that causes patients to be extremely sensitive to sunlight.

What was the FDA’s concern with bitopertin?

The FDA cited “uncertainties” about the correlation between the blood-based biomarker used in Disc’s clinical trials and actual clinical benefit for patients.

What happened to Disc Medicine’s stock price after the FDA’s decision?

Disc Medicine’s shares went down 31% to $49 in afternoon trading on Friday.

How will the FDA’s evolving approach to drug approvals impact the development of treatments for rare diseases?