Disc Medicine Advances Bitopertin Development As APOLLO Phase 3 Trial Reaches Full Enrollment

Disc Medicine, Inc. announced that the final participant has been randomised and dosed in its pivotal Phase 3 APOLLO trial evaluating bitopertin for the treatment of erythropoietic protoporphyria (EPP). Due to strong interest from patients and physicians, the study enrollment was increased from the originally planned 150 participants to 183.

The APOLLO trial is a global, double-blind, placebo-controlled Phase 3 study involving patients aged 12 and older with EPP and X-linked protoporphyria (XLP). Conducted across sites in the United States, Canada, Europe, and Australia, the study is designed to assess both clinical outcomes and biochemical markers associated with the condition.

“We are pleased to have completed enrollment in our APOLLO study in less than a year and we extend our gratitude to the EPP community for their continued contributions to the development of bitopertin,” said John Quisel, J.D., Ph.D., Chief Executive Officer and President of Disc. “The rapid enrollment of APOLLO underscores the urgent need and strong desire for a new treatment for EPP patients. We look forward to completing this study and continuing to engage with regulators to bring bitopertin to market.”

The co-primary endpoints include measuring the average monthly duration patients can tolerate sunlight without pain during peak daylight hours, as well as the percentage reduction in whole-blood metal-free protoporphyrin IX (PPIX) levels after 6 months of treatment. These endpoints aim to capture both symptomatic relief and underlying disease modification.

Topline data from the APOLLO trial are expected in the fourth quarter of 2026. Following this, the company plans to submit a Complete Response Letter (CRL) to the U.S. Food and Drug Administration, with a potential regulatory decision anticipated by mid-2027.