Disc Medicine Surges 60% After Phase 3 APOLLO Trial of Bitopertin Meets All Endpoints in Rare Sun-Sensitivity Disease

Disc Medicine, trading on Nasdaq under the ticker IRON, surged roughly 60% on October 19 after reporting that its pivotal Phase 3 APOLLO trial of bitopertin met all primary and secondary endpoints in patients with erythropoietic protoporphyria, a rare and painful disorder in which exposure to sunlight triggers severe reactions. The stock had already gained around 32% earlier in the session as investors anticipated the readout.

The APOLLO trial enrolled 183 adults and adolescents aged 12 and older with EPP or the related condition X-linked protoporphyria across sites in the United States, Canada, Europe, and Australia. Participants were randomized 1:1 to receive 60 mg oral bitopertin once daily or placebo for six months. The trial met co-primary endpoints of reducing protoporphyrin IX levels and increasing total time patients could spend in light, with all secondary endpoints also reaching statistical significance.

Bitopertin was developed in collaboration with Roche. Disc Medicine had previously aligned with the FDA that a successful APOLLO trial could serve as the basis for responding to a complete response letter, positioning the company for a potential regulatory filing. The readout completes the key late-stage catalyst the company flagged when it expanded the trial from its original enrollment target to 183 participants because of strong patient and physician demand.