Disc Medicine Shares Rise 31.5% on Day of Positive Phase 3 Results

Disc Medicine, Inc. (IRON) announced positive results Monday from its Phase 3 APOLLO trial, and a separate morning snapshot that day placed its shares 31.5% above Friday’s close. The trial tested bitopertin in patients with erythropoietic protoporphyria and X-linked protoporphyria, conditions that cause painful reactions to light.

At 10:00:16 a.m. ET (14:00:16 UTC) on Oct. 19, shares were quoted at $74.74, compared with a $56.84 close Friday, Oct. 16. The Monday reading was taken before the session ended, so it was not a closing price. Friday’s finish was up 19 cents, or 0.34%, from the previous session’s $56.65 close.

The 183-patient APOLLO study gave participants 60 mg of bitopertin or placebo daily for six months. In month six, patients taking bitopertin averaged 12.2 additional hours per month of pain-free time in light compared with those receiving placebo. The treatment also produced a 41.4% greater reduction than placebo in whole-blood metal-free protoporphyrin IX, a disease-related marker. The trial results add clinical-endpoint data to the company’s approval effort.

The Food and Drug Administration issued a complete response letter in February 2026 and declined to approve an earlier application. Earlier evidence had not established that changes in the blood marker predicted clinical benefit, and the agency sought evidence based on clinical endpoints. Bitopertin remains unapproved.

Disc Medicine plans to resubmit its application by the end of 2026 and anticipates an FDA decision by mid-2027. Those dates are the company’s expectations.