Silence Therapeutics’ Phase 2 Trial Shows Strong Efficacy of divesiran in Polycythemia Vera

Silence Therapeutics reported that its siRNA candidate divesiran met the primary endpoint in a phase 2 study of patients with polycythemia vera. The trial enrolled 48 participants and 88% of those receiving the drug achieved the predefined response, versus 19% on placebo.

Divesiran works by silencing the liver protein TMPRSS6, which reduces iron delivery to the bone marrow and slows the overproduction of red blood cells characteristic of the disease. Patients were considered responders when they required no phlebotomy and kept hematocrit levels below 45%.

The positive readout positions divesiran as a potential competitor to Takeda and Protagonist Therapeutics’ rusfertide, which is currently seeking FDA approval based on phase 3 data. Silence plans to move the program into late-stage development.