SIMPLIFY-1: Momelotinib Leads to Higher Transfusion Independence in MF

Momelotinib achieved higher rates of transfusion independence and reduced transfusion intensity over time compared with ruxolitinib in patients with myelofibrosis (MF) with anemia, according to a recent study.

The post hoc exploratory analysis of the double-blind, randomized, phase III SIMPLIFY-1 study was led by Vikas Gupta, MD, of the Princess Margaret Cancer Centre, and published in Leukemia & Lymphoma.

The primary endpoint was splenic response rate (spleen volume reduction ≥35% from baseline) at 24 weeks. Secondary endpoints included Total Symptom Score response rate (≥50% reduction from baseline) and transfusion independence rate at 24 weeks.

Patients with primary, post-polycythemia vera, or post-essential thrombocythemia MF were randomly assigned 1:1 to receive momelotinib or ruxolitinib. Of 432 total patients, 180 had moderate or severe anemia.

In patients with anemia, momelotinib was associated with higher rates of transfusion independence and stable or reduced transfusion intensity compared with ruxolitinib (93.2% vs 50.7%, respectively).

No new safety signals were observed. Adverse events included thrombocytopenia (n=3), dizziness (n=3), malaise (n=2), and hypotension (n=2) in the momelotinib group and thrombocytopenia (n=4) and acute myeloid leukemia (n=2) in the ruxolitinib group.

Evaluation in a larger population may be necessary, the authors noted, as SIMPLIFY-1 was not statistically powered to compare momelotinib and ruxolitinib in patient subgroups defined by baseline hemoglobin levels.

“Overall, momelotinib provides spleen, symptom, and anemia benefits to JAK inhibitor-naive patients with MF regardless of baseline hemoglobin level, and greater anemia-related benefits versus ruxolitinib in patients with hemoglobin levels less than 12 g/dL,” concluded Dr. Gupta and colleagues.

Reference

Gupta V, Oh S, Devos T, et al. Momelotinib vs. ruxolitinib in myelofibrosis patient subgroups by baseline hemoglobin levels in the SIMPLIFY-1 trial. Leuk Lymphoma. 2024. doi:10.1080/10428194.2024.2328800