{"id":2482,"date":"2026-08-10T00:00:00","date_gmt":"2026-08-10T04:00:00","guid":{"rendered":"https:\/\/www.insilens.com\/?p=2482"},"modified":"2026-08-13T00:03:10","modified_gmt":"2026-08-13T04:03:10","slug":"divesiran-hits-phase-2-pv-endpoint","status":"publish","type":"post","link":"https:\/\/www.insilens.com\/?p=2482","title":{"rendered":"Divesiran Hits Phase 2 PV Endpoint"},"content":{"rendered":"

Company:<\/strong> Silence Therapeutics · Event Type:<\/strong> Clinical\/Regulatory Signal · Product\/Asset:<\/strong> divesiran · Subject:<\/strong> Polycythemia Vera · Event Date:<\/strong> August 10, 2026<\/p>\n

\"Divesiran<\/p>\n

Summary<\/h4>\n

Silence Therapeutics reported that divesiran met the randomized Phase 2 SANRECO primary endpoint in phlebotomy-dependent polycythemia vera (PV). Clinical response occurred in 88% of divesiran-treated patients versus 19% with placebo, with activity preserved at both every-six-week and every-twelve-week schedules. The result is a high-importance, directionally positive hematology signal because it validates quarterly RNA interference against TMPRSS6 as a potential route to hematocrit control. Confidence remains limited by the 48-patient sample, topline disclosure and absence of comparative data against active cytoreductive therapy or rusfertide.<\/p>\n

What Happened<\/h4>\n

SANRECO is an ongoing global, randomized, double-blind, placebo-controlled study in 48 patients whose hematocrit remained uncontrolled and who required phlebotomy despite standard care that could include hydroxyurea, interferon and\/or ruxolitinib. Divesiran 6 mg\/kg produced a 93.8% response rate every six weeks and 81.3% every twelve weeks; response required no phlebotomy eligibility and hematocrit below 45% during weeks 18\u201336. Mean phlebotomies through week 36 were 0.2 with divesiran versus 2.1 with placebo. The company also reported improvements in iron markers and MPN-SAF symptom scores. Two grade 1 anemia events occurred, injection-site reactions were infrequent and self-limiting, and no new safety signal was reported. A quarterly Phase 3 placebo-controlled study is planned for the first half of 2027.<\/p>\n

Deep Analysis<\/h4>\n

Interpretation 1 \u2014 TMPRSS6 silencing may deliver differentiated, infrequent control of erythrocytosis by increasing hepcidin and restricting iron available for red-cell production. Supporting evidence includes a large placebo-adjusted response, concordant phlebotomy reduction and retained activity at quarterly dosing. Contradicting evidence is the small cohort, short controlled period and lack of mature thrombosis, durability or long-term anemia data.<\/p>\n

Interpretation 2 \u2014 the topline result may establish proof of mechanism without establishing best-in-class positioning. Supporting evidence includes the validated importance of hematocrit control and the convenience of quarterly dosing. Contradicting evidence includes a rapidly evolving PV landscape, notably rusfertide and established cytoreductive agents, plus the absence of active-comparator evidence, mutation-stratified outcomes and complete safety tables.<\/p>\n

Evidence that would upgrade the interpretation includes reproducible Phase 3 efficacy at every-twelve-week dosing, durable symptom improvement, fewer thrombotic events, stable iron indices without clinically meaningful anemia and practical dosing across background therapies. Evidence that would downgrade it includes Phase 3 effect-size compression, rebound hematocrit, problematic anemia, liver or platelet toxicity, or inability to differentiate from peptide hepcidin mimetics. A randomized active-comparator study showing no adherence, symptom, phlebotomy or safety advantage would falsify the stronger best-in-class thesis.<\/p>\n

Signal Extraction<\/h4>\n
    \n
  • Verified facts:<\/strong> randomized 48-patient Phase 2 design; 88% versus 19% primary-endpoint response; activity at six- and twelve-week dosing; large reduction in phlebotomy use; two grade 1 anemia events; Phase 3 planned for the first half of 2027.<\/li>\n
  • Company claim:<\/strong> divesiran could be first and best in class.<\/li>\n
  • Independent corroboration:<\/strong> trial registration and consistent Phase 1 pharmacology support the mechanism, but complete Phase 2 results are not yet peer reviewed.<\/li>\n
  • Missing facts:<\/strong> full adverse-event table, baseline balance, confidence intervals by dose, thrombosis outcomes, long-term durability, active-comparator performance, commercial dose and Phase 3 regulatory alignment.<\/li>\n<\/ul>\n

    Insilens Take<\/h4>\n

    Divesiran has moved from mechanistic promise to controlled clinical validation in a hematologic disease. The most defensible conclusion is that quarterly TMPRSS6 RNAi can produce substantial hematocrit and phlebotomy control over 36 weeks. It is premature to call the program best in class or to infer thrombosis prevention. The next value-defining evidence is a sufficiently powered Phase 3 study that confirms every-twelve-week efficacy and clarifies anemia, durability and comparative positioning.<\/p>\n

    Company and Product Background<\/h4>\n

    PV is a chronic myeloproliferative neoplasm, usually driven by JAK2 activation, in which excessive erythrocyte production increases blood viscosity and thrombosis risk. Standard management includes phlebotomy, aspirin and cytoreductive therapy. Divesiran is a liver-targeted short interfering RNA designed to reduce TMPRSS6, a negative regulator of hepcidin. Higher hepcidin limits intestinal iron absorption and iron release from stores, reducing iron availability for erythropoiesis and thereby lowering hematocrit without directly targeting the malignant JAK2 clone.<\/p>\n

    Importance and Confidence<\/h4>\n

    Signal Importance: 5\/5. Signal Direction: positive\/uncertain. Confidence in Facts: high. Confidence in Interpretation: medium-high. Red-team check: the title states a verified endpoint result and does not repeat the company\u2019s best-in-class claim. Importance reflects a controlled hematology readout and a competitive RNAi mechanism, not assumed approval or commercial success.<\/p>\n","protected":false},"excerpt":{"rendered":"

    Silence Therapeutics reported that divesiran met the randomized Phase 2 SANRECO primary endpoint in phlebotomy-dependent polycythemia vera (PV). Clinical response occurred in 88% of divesiran-treated patients versus 19% with placebo, with activity preserved at…<\/p>\n","protected":false},"author":5,"featured_media":2481,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1,11,3],"tags":[114,307],"class_list":["post-2482","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-all-categories","category-clinical","category-therapeutic-indication","tag-polycythemia-vera","tag-silence-therapeutics"],"blocksy_meta":[],"_links":{"self":[{"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/posts\/2482","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/www.insilens.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2482"}],"version-history":[{"count":1,"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/posts\/2482\/revisions"}],"predecessor-version":[{"id":2483,"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/posts\/2482\/revisions\/2483"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/media\/2481"}],"wp:attachment":[{"href":"https:\/\/www.insilens.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2482"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.insilens.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2482"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.insilens.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2482"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}