Core Insights - Deciphera Pharmaceuticals announced positive results from the Phase 2a IMPRSSION study of sapablursen for polycythemia vera (PV) at the 67th American Society of Hematology Annual Meeting [1][2] - The study demonstrated sapablursen's potential to reduce blood withdrawal rates and control hematocrit levels in phlebotomy-dependent PV patients [3][4] Company Overview - Deciphera Pharmaceuticals is a biopharmaceutical company focused on developing new medicines for cancer, neurologic, and autoimmune diseases, leveraging its proprietary switch-control kinase inhibitor platform [10] - The company is a member of Ono Pharmaceutical Co., Ltd., which aims to deliver innovative therapies and expand its global business [11] Study Details - The Phase 2a IMPRSSION study was a multicenter, randomized, open-label trial involving 49 patients, assessing the safety and efficacy of sapablursen [4] - Cohort A (32 patients) initially received 120 mg of sapablursen, later reduced to 80 mg, while Cohort B (17 patients) received 40 mg, administered subcutaneously every four weeks over a treatment period of 37 weeks [4] Efficacy Findings - The study achieved its primary endpoint, significantly decreasing the weekly phlebotomy rate from baseline to weeks 17-37: Cohort A decreased from 0.15 to 0.05 (p<0.0001) and Cohort B from 0.17 to 0.07 (p=0.0001) [7] - Median phlebotomies during the last 20 weeks of treatment were reduced to 0 in Cohort A and 1.5 in Cohort B, compared to 5 in the 26 weeks prior to treatment [7] Safety Profile - Sapablursen was generally safe and well tolerated, with one death due to acute myeloid leukemia deemed unrelated to the study drug [7][13] - Injection site reactions were mild, resolved spontaneously, and did not recur, with no adverse effects on liver or renal function observed [13] Regulatory Designations - Sapablursen received Fast Track designation in January 2024, orphan drug designation in August 2024, and Breakthrough Therapy designation in May 2025 from the U.S. FDA [3]