Erythropoietic protoporphyria is a rare inherited porphyria caused by disruption of heme biosynthesis that leads to protoporphyrin accumulation. It typically presents with severe, painful, non-blistering photosensitivity and may be complicated by hepatobiliary disease. Most cases are associated with pathogenic variants affecting ferrochelatase pathway function.
Disc Medicine has agreed with the FDA to resubmit bitopertin for rare blood disorder erythropoietic protoporphyria, with the agency allowing the Phase 3 APOLLO trial to support a new filing. The agreement follows a February rejection and could lead to a mid-2027 decision. Disc has implemented workforce cuts and its CFO sold shares amid the regulatory setback.
The FDA rejected accelerated approval for Disc Medicine's bitopertin for erythropoietic protoporphyria, citing insufficient evidence that biomarker reductions translate to clinical benefit. The agency wants to see results from the ongoing Phase 3 APOLLO trial before considering traditional approval, pushing any decision to at least mid-2027. Disc Medicine plans to address FDA concerns with APOLLO data expected in Q4 2026.
Disc Medicine will pursue traditional U.S. approval for bitopertin after the FDA declined to approve the rare disease drug under an accelerated review pathway, with a potential decision expected around mid-2027.
Disc Medicine received a complete response letter from the FDA for bitopertin in erythropoietic protoporphyria, with the agency requesting Phase 3 APOLLO trial results before approval. The company expects to respond by mid-2027.
The FDA issued a Complete Response Letter for Disc Medicine's bitopertin application for erythropoietic protoporphyria, citing concerns over surrogate endpoints despite review under the accelerated approval pathway and Commissioner's National Priority Voucher pilot program.
The FDA declined to approve Disc Medicine's bitopertin for erythropoietic protoporphyria on February 13, 2026, citing insufficient evidence linking biomarker reductions to clinical benefit. The company will pursue traditional approval using Phase 3 APOLLO trial data expected in Q4 2026.
The FDA rejected Disc Medicine's bitopertin for erythropoietic protoporphyria, citing uncertainties about clinical benefit despite the drug receiving a priority review voucher. The company will pursue traditional approval with Phase 3 data expected in late 2026.
The FDA issued a Complete Response Letter for bitopertin in erythropoietic protoporphyria, acknowledging the drug lowers PPIX levels but requiring Phase 3 APOLLO trial results to demonstrate clinical benefit before approval.
The FDA issued a Complete Response Letter for Disc Medicine's bitopertin New Drug Application for erythropoietic protoporphyria, requiring results from the ongoing Phase 3 APOLLO study before making an approval decision. Topline data is expected in Q4 2026.
Disc Medicine received a complete response letter from the FDA for bitopertin as a treatment for erythropoietic protoporphyria. The FDA acknowledged the drug lowers PPIX levels but requires evidence from the ongoing Phase 3 APOLLO study before approval.
| NCT ID | Title | Status | Phase |
|---|---|---|---|
| NCT06388642 |
Pharmacokinetics of Afamelanotide in Erythropoietic Protoporphyria Patients |
COMPLETED | PHASE1/PHASE2 |
| NCT05883748 |
HELIOS: Open-Label, Long-Term Extension Study to Investigate the Safety, Tolerability, and Efficacy of DISC-1459 (Bitopertin) in Participants With EPP or XLP |
ENROLLING_BY_INVITATION | PHASE2/PHASE3 |
| NCT05780840 |
Protection Against Visible Light by Dihydroxyacetone in Erythropoietic Protoporphyria |
UNKNOWN | NA |
| NCT05572125 |
Iron Therapy in Erythropoietic Protoporphyria |
COMPLETED | |
| NCT05308472 |
Study of Bitopertin to Evaluate the Safety, Tolerability, Efficacy, and PPIX Concentrations in Participants With EPP |
COMPLETED | PHASE2 |
| NCT05020184 |
Effect of Oral Cimetidine in the Protoporphyrias |
COMPLETED | PHASE2 |
| NCT04578496 |
A Safety Extension Study in Patients With Erythropoietic Protoporphyria (EPP) |
COMPLETED | PHASE3 |
| NCT04053270 |
Multicentre Phase III Erythropoietic Protoporphyria Study |
COMPLETED | PHASE3 |
| NCT03682731 |
Light Exposure Patterns and Symptoms Among Patients With Erythropoietic Protoporphyria |
COMPLETED | |
| NCT02979249 |
Oral Iron for Erythropoietic Protoporphyrias |
COMPLETED | NA |
