Dr Halpern on Momelotinib in Myelofibrosis With Anemia

Anna B. Halpern, MD, physician, assistant professor, Clinical Research Division, Fred Hutch; assistant professor, hematology, University of Washington School of Medicine, discusses symptom control, transfusion independence, and spleen volume findings with the JAK and ACVR1 inhibitor momelotinib vs the JAK inhibitor ruxolitinib (Jakafi) and danazol in patients with myelofibrosis with anemia.

The phase 3 SIMPLIFY-1 trial (NCT01969838) investigated the efficacy and safety of 24 weeks of treatment with momelotinib vs ruxolitinib in JAK inhibitor–naïve patients with myelofibrosis with anemia. In this trial, momelotinib improved anemia-related outcomes, including transfusion independence, Halpern says. Although symptom control was more effective with ruxolitinib than with momelotinib, the 2 agents generated similar spleen size control, Halpern explains. In total, 28.4% of patients in the momelotinib arm and 42.2% of those in the ruxolitinib arm achieved a 50% or greater total symptom score (TSS) reduction. At week 24, 26.5% and 29% of patients in the momelotinib and ruxolitinib arms, respectively, achieved at least a 35% reduction in spleen volume, showing that momelotinib was noninferior to ruxolitinib for spleen response (P = .011).

The phase 3 MOMENTUM trial (NCT04173494) evaluated the efficacy and safety of momelotinib vs danazol in patients with symptomatic anemia and myelofibrosis who had previous JAK inhibitor exposure. At week 24, 24.6% of patients in the momelotinib arm achieved a 50% or greater TSS reduction compared with 9.2% of patients in the danazol arm (P = .0095). Additionally, 23.1% of patients in the momelotinib arm achieved a 35% or greater reduction in spleen volume vs 3.1% of those in the danazol arm (P = .0006). Furthermore, the transfusion independence rates were 30.8% and 20.0% with momelotinib and danazol, respectively (1-sided P = .0064). When compared with danazol in patients who have previously received JAK inhibitors, momelotinib has several efficacy and safety benefits, Halpern concludes.