# Disc Medicine's Phase 3 Bitopertin Trial Meets Primary and Secondary Endpoints in EPP

- URL: https://stocks.freetheai.org/news/disc-medicine-s-phase-3-bitopertin-trial-meets-primary-and-secondary-endpoints-38de65
- Published: 2026-10-19T11:00:00Z
- Category: company_news; sentiment: bullish; impact: high
- Symbols: [NASDAQ:IRON](https://stocks.freetheai.org/symbols/NASDAQ-IRON)
- Written by our AI from expert market sources across the web for FreeTheAI Stocks, built by Vibhek Soni
- How write-ups are made: https://stocks.freetheai.org/how-we-write
- Not financial advice: https://stocks.freetheai.org/disclaimer

Disc Medicine, Inc. (NASDAQ:IRON) reported positive topline results from its pivotal Phase 3 APOLLO trial testing oral bitopertin in adults and adolescents with erythropoietic protoporphyria (EPP), including X-linked protoporphyria (XLP). The 183-patient trial met both co-primary endpoints and all secondary endpoints, demonstrating statistical significance over placebo across all key efficacy measures.

EPP is a rare genetic disorder that causes severe pain and skin reactions upon sunlight exposure due to the accumulation of toxic protoporphyrin IX. Patients taking a once-daily 60 mg dose of bitopertin achieved a 41.4% reduction in blood protoporphyrin IX levels relative to placebo and gained an average of 12.2 additional hours of pain-free time in light during the sixth month. The drug was generally well-tolerated, with dizziness as the most frequent side effect, and no high-grade adverse events reported.

Following the trial outcomes, Disc Medicine plans to resubmit a New Drug Application to the U.S. Food and Drug Administration by the end of 2026. A regulatory decision is anticipated by mid-2027, while detailed study findings will be presented at an upcoming medical conference.

## Key points

- The Phase 3 APOLLO trial of bitopertin met all primary and secondary endpoints in 183 patients with erythropoietic protoporphyria.
- Bitopertin reduced blood protoporphyrin IX by 41.4% and added 12.2 monthly hours of pain-free light exposure versus placebo.
- Bitopertin was generally well-tolerated, with dizziness being the most common adverse event and no Grade 3 or higher treatment-emergent side effects.
- Disc Medicine plans to resubmit a New Drug Application to the U.S. FDA by the end of 2026, with a decision expected by mid-2027.

## Questions and answers

### What were the results of Disc Medicine's Phase 3 APOLLO trial?

The Phase 3 APOLLO trial met all primary and secondary endpoints, showing a 41.4% reduction in blood PPIX and 12.2 additional monthly hours of pain-free light exposure for bitopertin compared to placebo.

### When does Disc Medicine plan to seek FDA approval for bitopertin?

Disc Medicine plans to resubmit a New Drug Application to the U.S. FDA by the end of 2026, expecting a regulatory decision by mid-2027.

### What side effects were observed in the bitopertin study?

Bitopertin was generally well-tolerated. Dizziness was the most common adverse event occurring in 50% of patients, and it was mild or moderate, with no adverse events above Grade 3.