On April 3, 2020, the United States Food and Drug Administration granted approval to luspatercept -aamt (hereafter designated luspatercept) for the treatment of anemia in adults with very low-, low-, or intermediate-risk myelodysplastic syndromes with ring sideroblasts (MDS-RS) or with myelodysplastic/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T) who require regular red blood cell (RBC) transfusions and failed an erythropoiesis stimulating agent (ESA). 1
Luspatercept is an erythroid maturation agent promoting late-stage red blood cell maturation. Its approval is based on the phase III MEDALIST trial ( NCT02631070) in which patients, with MDS-RS or MDS/MPN-RS-T who were RBC transfusion dependent and who failed prior ESA therapy or were ESA naïve, were randomized to receive luspatercept or placebo. 1 A higher proportion of patients treated with luspatercept (38%) showed RBC transfusion independence for at least 8 weeks within the first 24 weeks, compared to the placebo group (13%; p < 0.001). Additionally, a higher percentage of patients treated with luspatercept showed at least 12 weeks of independence in the first 24 weeks (28% vs 8% in luspatercept vs placebo group, respectively; p < 0.001) and 48 weeks (33% vs 12% in luspatercept vs placebo group, respectively; p < 0.001) of the trial compared to the placebo group. 2
Treatment-emergent adverse events of Grade 3 or 4 were reported in 42.5% of patients who received luspatercept vs 44.7% of patients who received placebo. 1 The most common (occurring in ≥ 10% of patients) all-grade adverse events included fatigue, diarrhea, asthenia, nausea, dizziness, and back pain. 2
This approval marks the second indication for luspatercept, which was already approved in the United States for the treatment of patients with beta thalassemia.