Silence Therapeutics reports positive Phase 2 topline data for divesiran in polycythemia vera

Silence Therapeutics plc announced on August 10, 2026 that its Phase 2 SANRECO trial of divesiran met its primary and secondary endpoints in patients with polycythemia vera (PV) who require repeated phlebotomy. The company described divesiran as a first-in-class siRNA tested in 48 phlebotomy-dependent PV patients, in a 36-week, randomized, double-blind, placebo-controlled trial evaluating subcutaneous doses of 6 mg/kg given either every six weeks (Q6W) or every twelve weeks (Q12W).¹

The primary endpoint, the proportion of patients achieving a response defined as no phlebotomy and hematocrit maintained below 45% during weeks 18 to 36, was met, with 88% of divesiran patients responding compared with 19% on placebo (p<0.0001).¹ Response rates were 93.8% in the Q6W group and 81.3% in the Q12W group.¹

A key secondary endpoint, phlebotomy rate during weeks 0 to 36, was also met, with a mean of 0.2 phlebotomies per patient in the divesiran groups versus 2.1 in the placebo group (p<0.0001).¹ The company also reported gains in hematocrit control, ferritin and other iron markers, and patient-reported symptom scores using the "MPN-SAF Total Symptom Score."

Silence said divesiran was well tolerated with safety consistent with prior trials, no new safety signals, infrequent and self-limiting injection site reactions, and two investigator-reported cases of grade 1 anemia.¹

Based on these Phase 2 results, the company expects to start a Phase 3 trial comparing divesiran Q12W dosing to placebo in the first half of 2027.¹ Silence said it plans to present full Phase 2 results at a future medical congress.¹ Divesiran holds FDA Fast Track and Orphan Drug designations for PV.¹