FDA Rejects Disc Medicine’s Bitopertin for EPP After Questioning Surrogate Endpoint
The agency said Phase 2 data did not show that lowering PPIX predicts sunlight-exposure benefits, steering the program to await Phase 3 APOLLO results.
Overview
- Disc Medicine received a Complete Response Letter on Feb. 13 declining accelerated approval for bitopertin in erythropoietic protoporphyria.
- FDA reviewers acknowledged AURORA and BEACON showed significant reductions in whole blood metal-free PPIX but found no link to sunlight-exposure clinical endpoints.
- The regulator indicated results from the ongoing APOLLO Phase 3 trial could support traditional approval, with topline data expected in Q4 2026.
- Disc said it will request a Type A meeting and plans to respond to the CRL after APOLLO, targeting an updated FDA decision by mid-2027.
- Shares of Disc Medicine fell more than 20% following the announcement, which came after review under the FDA’s National Priority Voucher pilot.