Safety and efficacy of luspatercept in treating anemia associated with myelodysplastic syndrome with ring sideroblasts in Asian patients who require red blood cell transfusions: a phase II bridging study.

BACKGROUND

Patients with lower-risk myelodysplastic syndromes (MDS) may experience anemia and a high transfusion burden, alongside a risk of progression to acute myeloid leukemia. Luspatercept, a recombinant fusion protein that acts as an erythroid maturation agent, was FDA/EMA-approved in 2020 based on the phase III MEDALIST trial. There remains an unmet need for anemia treatment in Asian patients for whom red blood cell (RBC) transfusion is a standard of care, and in whom rates/severity of anemia and serum erythropoietin levels are often higher versus Western patients.

OBJECTIVES

The objective of this study was to assess the efficacy, safety, and tolerability of luspatercept in Asian patients with anemia due to transfusion-dependent lower-risk MDS with ring sideroblasts.

DESIGN

This was a phase II, single-arm, interventional bridging study (NCT04477850).

METHODS

Patients from China and Japan with very low-, low-, or intermediate-risk MDS with ring sideroblasts who were RBC transfusion-dependent received subcutaneous luspatercept starting at 1.0 mg/kg every 3 weeks. The primary endpoint was RBC transfusion independence (TI) ⩾8 weeks (weeks 1-24).

RESULTS

There was a statistically significant, clinically meaningful improvement of anemia in Asian patients; 60% (n = 18, p < 0.0001) achieved RBC-TI for ⩾8 weeks and 43% (n = 13) for ⩾12 weeks (weeks 1-24). Safety was consistent with the known profile of luspatercept in MDS.

CONCLUSION

These results support luspatercept as a well-tolerated, efficacious alternative to transfusions for Asian patients with lower-risk MDS, who tend to have more severe anemia. Trial registration: clinicaltrials.gov, NCT04477850.