The FDA has approved luspatercept-aamt for the treatment of anemia that requires 2 or more red blood cell transfusions over 8 weeks in adults with very low- to intermediate-risk myelodysplastic syndromes with ring sideroblasts (MDS-RS) or with myelodysplastic/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T). The approval was limited to patients with these subtypes of MDS who have either not responded to an erythropoiesis-stimulating agent (ESA), previously responded to an ESA but lost response, or are unlikely to respond to ESA therapy because of a high serum erythropoietin level (>200 U/L).
FDA approval was based on results from the MEDALIST trial, which enrolled 229 patients with very low–, low-, or intermediate-risk MDS-RS that was transfusion-dependent.
Participants in the trial were randomized 2:1 to luspatercept-aamt or placebo. All patients received supportive care, including red blood cell (RBC) transfusions.
The primary endpoint of the study was the proportion of patients who were RBC-transfusion independent (RBC-TI) during any 8-week period between weeks 1 and 24 of treatment.
Of the 153 patients in the luspatercept-aamt group, 58 were RBC-TI (37.9%; 95% CI 30.2-46.1), compared with 10 patients who received placebo (13.2%; 95% CI 6.5-22.9), yielding a treatment difference of 24.6% (p<0.0001).
The most common adverse reactions to luspatercept-aamt, occurring in >10% of patients, included fatigue, headache, musculoskeletal pain, arthralgia, dizziness/vertigo, nausea, diarrhea, cough, abdominal pain, dyspnea, and hypersensitivity.
Source: FDA press release, April 3, 2020.