Fedratinib Induces Spleen Responses And Reduces Symptom Burden In Patients With Myeloproliferative Neoplasm (Mpn)-Associated Myelofibrosis (Mf) And Low Platelet Counts, Who Were Either Ruxolitinib-Naive Or Were Previously Treated With Ruxolitinib

Introduction: Cytopenias are a leading cause of ruxolitinib (RUX) discontinuation for patients (pts) with myelofibrosis (MF). Though RUX 5 mg BID is recommended for pts with platelet (PLT) counts of 50 to <100 × 109/L, this regimen can increase risk of thrombocytopenia with minimal benefit on splenomegaly or symptom burden. Fedratinib (FEDR) is an oral, selective inhibitor with activity against wild-type and mutant JAK2 that was assessed as first-line MF treatment (Tx) in the placebo (PBO)-controlled, phase III JAKARTA study, and as post-RUX Tx in the single-arm, phase II JAKARTA2 study. Here we report the efficacy and safety of FEDR 400 mg QD in JAKARTA and JAKARTA2 pts with baseline (BL) PLT counts of <100 × 109/L (“<100”) or ≥100 × 109/L (“≥100”).