Long-Term Efficacy and Safety of Luspatercept for Transfusion-Dependent β-Thalassemia

In 2019, the U.S. FDA approved luspatercept to treat anemia in adults with transfusion-dependent β-thalassemia, including those with hemoglobin E/β-thalassemia, based on the primary analysis of the industry-funded, double-blind, randomized, placebo-controlled BELIEVE trial (NEJM JW Oncol Hematol Mar 26 2020 and N Engl J Med 2020; 382:1219), which showed a significant reduction in transfusion burden with luspatercept at a median follow-up of 64 weeks. Now, the investigators report results from a 5-year, open-label extension phase, with a median luspatercept treatment period of 154 weeks.

The transfusion burden continued to decrease with luspatercept: mean decreases from baseline were 4.8 red blood cell units in weeks 1 to 48, 5.8 units in wee…