Efficacy of Momelotinib in Reducing Anemia in MF Confirmed With Real-World Data

A real-world, retrospective analysis showed that momelotinib reduces anemia in patients with myelofibrosis (MF), with many achieving transfusion independence and increasing hemoglobin levels over time. Symptom alleviation, reduced splenomegaly, and acceptable safety profiles were consistent with clinical trial data.

Anemia is a common symptom of MF. The Janus kinase (JAK) inhibitor ruxolitinib, which is the standard of care for treating patients with MF, does not address this anemia burden. Momelotinib, an MF-approved combined JAK and activin A receptor type-1 inhibitor positively affects anemia status in addition to alleviating MF symptoms, including splenomegaly.¹ In a retrospective analysis, Dr. Lucía Pérez-Lamas, Hospital Universitario Puerta de Hierro, Madrid, Spain, and colleagues investigated the safety and efficacy of momelotinib in a real-world setting.²

The retrospective analysis included patients with MF, anemia, and splenomegaly who were administered momelotinib between March 2023 and July 2024 through a managed-access program across 74 centers in Spain. Of the 154 included patients, 77% had previously received an erythropoietin- stimulating agent; 26 had received momelotinib as first-line therapy, and the remaining 128 had received a median of 1.2 prior lines including JAK inhibitors (mainly ruxolitinib). The median age of included patients was 73 years, and more than 80% of patients were considered to be Dynamic International Prognostic Scoring System intermediate-2 or high risk. The mean hemoglobin concentration was 8 g/dL (range, 4.7–13.5 g/dL), and 70.1% of patients were transfusion dependent.

Most patients who had received momelotinib had reduced pruritus, asthenia, sweating, anorexia, and abdominal discomfort. Transfusion dependence was reduced from 74.7% to 45.6% in the overall cohort, which was more pronounced in the JAK inhibitor–exposed patients. In addition, among patients who remained transfusion dependent, the median required number of red blood cell (RBC) units per month was reduced from 4 to 2.25 per month. Only 8.1% of patients required a higher transfusion intensity, and 50.8% required a lighter one. Similarly, 62.2% of patients presented with spleen reductions with a median decrease of 5 cm (interquartile range, 2–15), but only 24.4% met the 2013 European LeukemiaNet criteria for reduction in spleen volume.

Thrombocytopenia, infections, and hepatotoxicity were the most common grade 3/4 adverse events; however, the platelet count remained stable throughout the treatment. At the timepoint of the last follow-up (median of 5.48 months), 79% of participants continued their treatment.

In conclusion, momelotinib is a safe alternative to ruxolitinib that promotes high levels of transfusion independence. The real-world data are consistent with clinical trial results.

1. Verstovsek S, et al. Lancet. 2023;401(10373):269-280.
2. Pérez-Lamas L, Segura Diaz A, García Delgado R, et al. Real-world outcomes of momelotinib as an alternative therapy to other JAK inhibitors in myelofibrosis patients with anemia. Abstract #1790. Presented at the American Society of Hematology Annual Meeting; December 7-10, 2024; San Diego, California.