London, August 10, 2026
Silence Therapeutics plc announced positive topline results from the Phase 2 SANRECO trial of divesiran in patients with polycythemia vera (PV), a rare blood cancer characterized by excessive production of red blood cells. The randomized, double-blind, placebo-controlled study met its primary endpoint, with 88% of patients receiving divesiran achieving a clinical response compared with 19% for placebo, representing a placebo-adjusted response rate of 69%. Both dosing schedules demonstrated substantial efficacy, with response rates of 93.8% for once-every-six-weeks dosing (Q6W) and 81.3% for once-every-12-weeks dosing (Q12W). The company said divesiran was well tolerated, with no new safety findings identified. Based on the results, Silence Therapeutics plans to advance divesiran into a Phase 3 trial in polycythemia vera, expected to begin in the first half of 2027.
SANRECO Trial Achieves Primary Endpoint
The Phase 2 SANRECO trial evaluated 48 phlebotomy-dependent patients with polycythemia vera who had uncontrolled hematocrit despite standard treatments that could include hydroxyurea, interferon and ruxolitinib. The primary endpoint measured the proportion of patients achieving a response during weeks 18 through 36, defined as maintaining hematocrit below 45% without requiring phlebotomy. The study showed a statistically significant advantage for divesiran, with 88% of treated patients achieving a response versus 19% with placebo, with a significance level of p<0.0001. The key secondary endpoint also demonstrated a meaningful reduction in phlebotomy requirements, with patients receiving divesiran undergoing an average of 0.2 phlebotomies compared with 2.1 for placebo during the 36-week period. Improvements were also observed in hematocrit control, iron-related markers including ferritin, and patient-reported symptoms measured using the MPN-SAF Total Symptom Score.
Divesiran Shows Efficacy With Infrequent Dosing
Importantly, both evaluated divesiran schedules produced strong clinical responses. Patients receiving the treatment every six weeks achieved a 93.8% response rate, while those receiving treatment every 12 weeks achieved an 81.3% response rate. The findings suggest that divesiran may potentially provide durable hematocrit control with relatively infrequent dosing, an important consideration for patients who currently depend on repeated blood removal procedures to control hematocrit. Silence Therapeutics reported that divesiran was generally well tolerated and that its safety profile remained consistent with previous clinical studies. Injection-site reactions were infrequent and self-limiting, while two investigator-reported Grade 1 anemia adverse events were observed. No new safety signals were identified. The company plans to present the complete SANRECO Phase 2 dataset at an upcoming medical congress.
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Silence Therapeutics Plans Phase 3 Development
Silence Therapeutics plans to evaluate divesiran Q12W versus placebo in a Phase 3 polycythemia vera trial, with initiation anticipated in the first half of 2027. Divesiran is an investigational siRNA therapy developed using the company’s proprietary mRNAi GOLD™ platform, which is designed to silence specific disease-associated genes. The therapy targets TMPRSS6, a liver-expressed regulator of hepcidin, the body’s master regulator of iron metabolism. By silencing TMPRSS6, divesiran is designed to increase hepcidin activity and restrict iron availability to the bone marrow, potentially reducing excessive red blood cell production. Silence Therapeutics believes this mechanism could provide a new approach to managing PV, where maintaining hematocrit below 45% is an important treatment goal. The company said the positive SANRECO results strengthen the potential of divesiran as a first-in-class and potentially best-in-class siRNA treatment for PV and support its transition toward late-stage development.
Source: Silence Therapeutics press release
