Pacritinib

Current understanding

JAK2/IRAK1 inhibitor approved for myelofibrosis with severe thrombocytopenia (platelets < 50K).

Evidence log

• 2026-09-01 — Matching-Adjusted Indirect Comparison of Gecacitinib, Fedratinib, Pacritinib, and Momelotinib in Second-Line Myelofibrosis Therapy.: MAIC (observational) in ruxolitinib-pretreated MF placed pacritinib below gecacitinib on spleen-volume and symptom responses, with higher GI adverse-event and discontinuation rates in the indirect comparison. (novelty: 3)
• 2026-08-14 — Janus kinase inhibitors after ruxolitinib failure in myelofibrosis: A systematic review and pooled analysis of phase 3 efficacy and integrated safety across clinical trials and real-world evidence.: Systematic review + pooled analysis of phase-3 and real-world evidence confirms pacritinib’s preferential role in post-ruxolitinib patients with severe thrombocytopenia, with a spleen/symptom/safety fingerprint distinguishable from fedratinib and momelotinib and useful for phenotype-guided second-line JAKi choice. (novelty: 3)
• 2026-07-01 — Phase I Trial of Pacritinib in Combination With Venetoclax and Azacitidine for the Treatment of Accelerated and Blast Phase Myeloproliferative Neoplasms: Phase I trial (trial-early) evaluating pacritinib + venetoclax + azacitidine triple combination in accelerated and blast phase MPN — extends pacritinib’s role in AP/BP-MPN by layering BCL-2 inhibition onto the JAK/HMA backbone, targeting multiple pathways in a population with no standard of care. (novelty: 4)
• 2026-03-04 — Pacritinib With Standard of Care Azacitidine or Decitabine as a Bridge to Allogeneic Hematopoietic Stem Cell Transplant for Patients With Accelerated and Blast Phase Myeloproliferative Neoplasms: Phase II trial (trial-early) evaluates pacritinib added to standard-of-care azacitidine or decitabine as a bridge to allogeneic HSCT in accelerated/blast phase MPN, with primary endpoint being the proportion of patients successfully proceeding to transplant — extends pacritinib’s role into AP/BP-MPN bridging, complementing thrombocytopenia-friendly profile. (novelty: 3)
• 2026-03-05 — Pacritinib vs. Hydroxyurea in Advanced Proliferative Chronic Myelomonocytic Leukemia: Randomized trial (trial-early) launched comparing pacritinib BID vs hydroxyurea for up to 48 weeks in adults with advanced proliferative CMML — first head-to-head evaluation of pacritinib in this population, extending its use beyond MF/MDS into proliferative CMML. (novelty: 3)
• 2026-02-06 — Pacritinib For Bone Marrow Fibrosis In Patients With Myelofibrosis Who Have Thrombocytopenia: PACRIMYEL phase II trial (trial-early) tests pacritinib’s dual JAK2/IRAK1 inhibition (JAK-STAT + NF-κB co-blockade) for bone marrow fibrosis regression and cytopenia improvement in MF patients with moderate thrombocytopenia (platelets 50–120 ×10⁹/L), with structured imaging endpoints — first prospective study of pacritinib’s antifibrotic effect. (novelty: 4)
• 2026-04-08 — A Clinical Trial of Flonoltinib Maleate Tablets in the Treatment of JAK Inhibitor Refractory/Relapsed/Intolerant Patients With Medium to High Risk Myelofibrosis: cross-connection with flonoltinib-maleate-mpn: Shares the platelet-count-stratified dosing concept and the JAKi-failure population currently addressed by pacritinib/momelotinib. (novelty: 4)
• 2026-02-25 — A Phase 3 Study of Pacritinib in Patients With Primary Myelofibrosis, Post Polycythemia Vera Myelofibrosis, or Post-Essential Thrombocythemia Myelofibrosis: Phase 3 randomized trial (trial-late) of pacritinib 200 mg BID vs physician’s choice in ~399 MF patients with severe thrombocytopenia (platelets <50K/μL) — confirmatory study to establish efficacy and safety in this high-risk subpopulation, building on PERSIST and PAC203. (novelty: 3)
• 2026-03-16 — Decitabine With Ruxolitinib, Fedratinib or Pacritinib for the Treatment of Accelerated/Blast Phase Myeloproliferative Neoplasms: Phase II trial (trial-early): pacritinib being evaluated as one of three JAK inhibitor options combined with decitabine as pre-transplant bridging therapy in accelerated/blast phase MPN — extends pacritinib use into AP/BP-MPN, particularly relevant for thrombocytopenic patients. (novelty: 3)
• 2026-03-18 — Selinexor and Pacritinib in JAK Inhibitor-naïve MF Patients With Cytopenias: Phase II trial (trial-early) launched evaluating pacritinib in combination with the XPO1 inhibitor selinexor in JAK inhibitor-naïve myelofibrosis patients with anemia and thrombocytopenia — a novel dual-pathway approach for cytopenic MF. (novelty: 4)
• 2026-04-27 — Pacritinib, a Kinase Inhibitor of CSF1R, IRAK1, JAK2, and FLT3, in Adults and Pediatric Participants 12 Years of Age or Older With Myelodysplastic Syndromes or Myelodysplastic/Myeloproliferative Neoplasms: Phase I/II trial (trial-early) launched evaluating pacritinib in adults and pediatric patients ≥12 years with MDS or MDS/MPN, leveraging its CSF1R/IRAK1/JAK2/FLT3 inhibition profile to assess safety, dosing, and efficacy over up to 8 years — first prospective study extending pacritinib beyond myelofibrosis. (novelty: 3)

Open questions

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