GSK announces new 48-week data from MOMENTUM Phase 3 trial

GSK announced new 48-week data from the MOMENTUM phase III trial that showed a majority of patients treated with investigational momelotinib maintained their responses across key clinical measures including Total Symptom Score, Transfusion Independence rate, and Splenic Response Rate in myelofibrosis patients previously treated with an approved Janus kinase inhibitor. Additionally, new analyses from MOMENTUM showed that TI response with momelotinib at week 24 was associated with overall survival. MOMENTUM is a global, randomized, double-blind phase III clinical trial of momelotinib versus danazol in patients with myelofibrosis who were symptomatic and anemic and had been previously treated with an approved JAK inhibitor. The study was designed to evaluate the safety and efficacy of momelotinib for the treatment and reduction of the key manifestations of the disease: constitutional symptoms, blood transfusions and enlarged spleen. Patients were randomized at 2:1 to receive either momelotinib or danazol. After 24 weeks of treatment, patients on danazol were allowed to crossover to receive momelotinib. Early crossover to momelotinib was available for confirmed splenic progression. Primary analysis at week 24 met the primary endpoint of TSS reduction of greater than or equal to50% over the 28 days immediately before the end of week 24 compared to baseline TSS, using the Myelofibrosis Symptom Assessment Form. It also met key secondary endpoints including TI rate for greater than or equal to12 weeks immediately before the end of week 24 with hemoglobin levels greater than or equal to8 g/dL and SRR based on splenic volume reduction of greater than or equal to35% at week 24 from baseline. In MOMENTUM, the most common Grade 3 or greater treatment emergent adverse events in the open-label period, similar to the double-blind period, were thrombocytopenia and anemia. Additionally, these efficacy and safety results in patients with thrombocytopenia were consistent with the overall population. An additional analysis from the MOMENTUM clinical trial evaluated the impact of TI response on overall survival. As previously presented, patients receiving treatment with momelotinib were more likely to achieve transfusion independence during the study period than patients treated with danazol. Momelotinib patients were also less likely to require a transfusion during the study period, and more likely to reduce transfusion burden. Data presented at ASH with additional survival follow up suggests that TI response with momelotinib at week 24 is associated with overall survival compared to patients who were not TI. A New Drug Application and Marketing Authorization Application for momelotinib is currently under review with the US Food and Drug Administration and European Medicines Agency, respectively. Momelotinib is not currently approved in any market.