The European Medicines Agency Review of Luspatercept for the Treatment of Adult Patients With Transfusion-dependent Anemia Caused by Low-risk Myelodysplastic Syndromes With Ring Sideroblasts or Beta-thalassemia

Luspatercept is a recombinant fusion protein that selectively binds to ligands belonging to the transforming growth factor-beta superfamily, resulting in erythroid maturation and differentiation. On June 25, 2020, a marketing authorization valid through the European Union (EU) was issued for luspatercept for the treatment of adult patients with transfusion-dependent anemia caused by very low-, low-, and intermediate-risk myelodysplastic syndromes (MDS) with ring sideroblasts, or those with transfusion-dependent beta thalassemia (BT). Luspatercept was evaluated in 2 separate phase 3, double-blind, placebo-controlled multicentre trials. The primary endpoints of these trials were the percentage of patients achieving transfusion independence over ≥8 weeks or longer for patients with MDS, and the percentage of patients achieving a ≥33% reduction in transfusion burden from baseline to week 13–24 for patients with BT. In the MDS trial, the percentage of responders was 37.91% versus 13.16%, P < 0.0001, for patients receiving luspatercept versus placebo, respectively. In the BT trial, the percentage of responders was 21.4% versus 4.5% ( P < 0.0001) for luspatercept versus placebo, respectively. Treatment with luspatercept led to similar incidences of adverse events (AEs), but higher incidences of grade ≥3 AEs and serious AEs compared to placebo. The most frequently reported treatment-emergent AEs (≥15%) in the pooled luspatercept group were headache; back pain, bone pain, and arthralgia; diarrhea; fatigue; pyrexia; and cough. The aim of this article is to summarize the scientific review of the application, which led to the regulatory approval in the EU.