Disc Medicine Shares Decline Following Phase 2 DISC-3405 Results

Disc Medicine reported positive Phase 2 results for its investigational drug DISC-3405 in treating polycythemia vera, though the company's shares fell nearly 5% following the announcement. Data from the RESTORE-PV trial suggests the treatment reduces the need for phlebotomy, a standard procedure for patients with the blood disorder.

"This first look at data from the RESTORE-PV trial shows that the established pharmacodynamics of DISC-3405 are translating well on important clinical measures," said John Quisel, JD, PhD, President and Chief Executive Officer of Disc Medicine, in a statement.

Clinical Efficacy in the RESTORE-PV Trial

The trial data indicates a reduction in the dependency on phlebotomy, which is the primary treatment for polycythemia vera to manage elevated red blood cell counts. According to the company's report, 61.5% of participants in Cohort A remained phlebotomy-free throughout the 26-week study period. The mean total number of phlebotomy events per participant dropped from 4.0 at baseline to 0.6 during the trial.

DISC-3405 is an investigational anti-TMPRSS6 monoclonal antibody. It functions by increasing hepcidin production, which suppresses serum iron. By regulating iron levels, the drug aims to control the overproduction of red blood cells characteristic of polycythemia vera.

Market Performance and Investor Reaction

The market reaction was negative despite the clinical progress. Disc Medicine (IRON) stock closed at $70.44 on September 11, 2026, marking a decline of 4.99% for the day.

What Is at Stake for Patients

Polycythemia vera is a chronic condition that requires ongoing medical intervention to prevent complications like blood clots or strokes. Current treatment protocols rely on regular phlebotomy to physically remove blood from the body, which can be taxing for patients. The development of a monoclonal antibody that targets the underlying mechanism of iron regulation represents a shift toward pharmacological management, which may reduce the frequency of physical procedures required for long-term maintenance.