Disc challenges in polycythemia vera, but Silence retains the lead

Disc Medicine is preparing a competitive challenge in polycythemia vera (PV) with DISC-3405, its Phase 2 monoclonal-antibody treatment targeting the TMPRSS6/hepcidin pathway. Data were expected in the third quarter of 2026.

Silence Therapeutics currently leads on clinical evidence after divesiran produced an 88% response rate in the Phase 2 SANRECO trial, compared with 19% for placebo, among 48 phlebotomy-dependent PV patients.

Divesiran’s results were broadly consistent across dosing schedules:
approximately 93.8% response with dosing every six weeks and 81.3% with dosing every 12 weeks. Patients also required fewer phlebotomies and showed improved hematocrit control.

Silence plans to advance divesiran into Phase 3 development, potentially using quarterly dosing, with regulatory discussions underway and a trial expected to begin in the first half of 2027.

The strong Silence data validate the hepcidin-focused treatment approach but raise the efficacy bar for Disc and other competitors. The companies are also chasing Takeda and Protagonist Therapeutics’ rusfertide, which recently received FDA approval according to the report.