The FDA said in a letter to the company published on Friday that the data submitted by the company is insufficient proof of clinical benefit for bitopertin.
- The agency said that the company must provide evidence of clinical benefit from “adequate and well-controlled trial(s)” for approval.
- Disc Medicine’s bitopertin is one of the 18 drugs to currently have been tapped for fast review by the FDA under its Commissioner's National Priority Voucher program.
- Disc said it would resubmit its application following the completion of its APOLLO trial and expects a fresh decision from the agency by mid-2027.
Shares of Disc Medicine (IRON) slumped 21% on Friday after the U.S. Food and Drug Administration refused to approve the company’s bitopertin oral tablets for the treatment of Erythropoietic Protoporphyria.
Disc Medicine’s Bitopertin is one of the 18 drugs to currently have been tapped for fast review by the FDA under its Commissioner's National Priority Voucher program announced in June 2025. The program aims to reduce FDA assessment time to one to two months from the standard 10 to 12 months.
FDA’s Rationale
The FDA said in a letter to the company published on Friday that the data submitted by the company is insufficient proof of clinical benefit. The agency said that the company must now provide evidence of clinical benefit from “adequate and well-controlled trial(s)” for approval.
The agency also expressed willingness to meet with the company to discuss options including the completion of an ongoing late-stage trial called Apollo and using it to seek a traditional approval.
Disc Medicine was seeking approval of the pill in Erythropoietic Protoporphyria, a rare, inherited metabolic disorder causing extreme sensitivity to sunlight and artificial light, leading to immediate, painful skin reactions like burning, redness, and swelling.
The company confirmed the receipt of the letter and said that it expects to seek a meeting with the agency.
“The CRL will delay the potential approval of bitopertin, but we have confidence in the ongoing APOLLO trial…,” CEO John Quisel said. The company also added that the issues raised by the FDA in the letter are “readily addressable” with data from its APOLLO trial expected in the fourth quarter (Q4).
The company said it would resubmit its application following the completion of the APOLLO trial and expects a fresh decision from the agency by mid-2027.
Last month, Reuters reported that the FDA has delayed the review of bitopertin after its scientists flagged safety and efficacy concerns. The decision was previously slated for January-end but pushed back two weeks.
How Did Stocktwits Users React?
On Stocktwits, retail sentiment around IRON stock jumped from ‘bearish’ to ‘bullish’ territory over the past 24 hours, while message volume increased from ‘normal’ to ‘high’ levels.
A Stocktwits user now expects the FDA to decide on an approval for the pills only by late 2027. “Debating whether to start a small position now or wait for further downside,” they wrote.
IRON stock has gained 5% over the past 12 months.
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