Disc Reports Topline Results from Phase 2 AURORA Study of Bitopertin in Patients with Erythropoietic Protoporphyria (EPP)

• Met primary endpoint, demonstrating dose-dependent, statistically significant reductions in protoporphyrin IX (PPIX) compared to placebo in both 20 mg and 60 mg dose groups
• Improved measures of light tolerance, including the key secondary endpoint, in both 20 mg and 60 mg dose groups, but did not meet statistical significance compared to placebo
• Dose-dependent reductions in the rate of phototoxic reactions with pain, with statistical significance at the 60 mg dose group compared to placebo
• Dose-dependent improvements in the Patient Global Impression of Change (PGIC), with statistical significance at the 60 mg dose group compared to placebo
• Investor webcast at 8:30 am ET to discuss top-line data

WATERTOWN, Mass., April 01, 2024 (GLOBE NEWSWIRE) -- Disc Medicine, Inc. (NASDAQ:IRON), a clinical-stage biopharmaceutical company focused on the discovery, development, and commercialization of novel treatments for patients suffering from serious hematologic diseases, today presented topline data from AURORA, a phase 2 study of bitopertin in patients with EPP. Treatment with bitopertin resulted in statistically significant reductions in PPIX, the primary endpoint, and significant improvements in the rate of phototoxic reactions with pain and the Patient Global Impression of Change (PGIC). On the key secondary endpoint of cumulative time in sunlight on days without pain, bitopertin patients had a positive response consistent with BEACON results, but the endpoint did not meet statistical significance due to strong placebo performance.

“This study has confirmed that bitopertin significantly reduces the toxic metabolite, PPIX, in patients with EPP, and we have shown that bitopertin-treated patients experience improvements in the clinically meaningful outcomes of Patient Global Impression of Change and the number and rate of phototoxic reactions with pain, with the 60 mg dose reaching statistical significance compared to placebo. Despite the strong performance of bitopertin on the key secondary endpoint of cumulative time in light, consistent with results seen in BEACON, statistical significance was not met due to an outsized placebo response,” said John Quisel, J.D., Ph.D., President and Chief Executive Officer. “Given that, we will need to conduct an analysis of our final data set and work with investigators, regulators, and patient advocacy groups to define the optimal registrational endpoints moving forward. While we do this additional work, we continue to be excited about the upcoming readouts from our other programs, including updated data from our DISC-0974 study in anemia of myelofibrosis in Q2.”

The AURORA study is a randomized, double-blind, placebo-controlled phase 2 study that enrolled 75 adult subjects with EPP. Subjects were randomized 1:1:1 to receive 20 mg of bitopertin, 60 mg of bitopertin, or placebo once daily for 17 weeks.

Summary of topline results

Primary endpoint

• Bitopertin resulted in significant, dose-dependent, and sustained reductions in whole blood PPIX levels: -21.6% for 20 mg (p=0.003 vs placebo) and -40.7% for 60 mg (p