A randomized phase 3 trial designed to evaluate luspatercept among patients with myelodysplastic syndrome with chronic anemia met its primary endpoint, according to the agent’s manufacturer.

Luspatercept (Celgene and Acceleron) is a first-in-class erythroid maturation agent that is believed to regulate late-stage red blood cell maturation. Luspatercept (ACE-536) is an experimental drug in clinical trials for the treatment of anemia in beta-thalassemia and myelodysplastic syndromes.

Acceleron Pharma is developing it in collaboration with Celgene. Phase III trials are evaluating the efficacy of luspatercept for the treatment of anemia in the hematological disorders beta-thalassemia and myelodysplastic syndromes.

Luspatercept is a recombinant fusion protein derived from human activin receptor type IIb (ActRIIb) linked to a protein derived from immunoglobulin G. The FDA awarded orphan drug status in 2013 and fast track designation in 2015 for both indications

The double-blind, multicenter MEDALIST trial evaluated the safety and efficacy of luspatercept versus placebo among patients with very low-, low- or intermediate-risk myelodysplastic syndrome with chronic anemia.

Red blood cell transfusions

All study participants were refractory to, intolerant of or ineligible for treatment with an erythropoietin-stimulating agent. They also rang sideroblast-positive and required frequent red blood cell transfusions.

Researchers observed a statistically significant improvement in the primary endpoint of red blood cell transfusion independence of at least 8 consecutive weeks during the first 24 weeks among luspatercept-treated patients.

The trial also met its secondary endpoint of a statistically significant improvement in red blood cell transfusion independence of at least 12 consecutive weeks during the first 24 weeks.

The trial also met another secondary endpoint of modified hematologic improvement-erythroid. Luspatercept appeared well tolerated, with an adverse event profile consistent with previously published data. Full results from the MEDALIST trial will be submitted for presentation at an upcoming medical meeting.

“This result from the phase 3 MEDALIST trial demonstrates the potential clinical benefit of luspatercept as an erythroid maturation agent for the treatment of chronic anemia in patients with the low-to-intermediate risk myelodysplastic syndrome,” Jay Backstrom, MD, the chief medical officer at Celgene, said in a company-issued press release.

“Based on these results, we look forward to preparing the dossier for global regulatory submissions and also investigating the clinical potential of luspatercept in erythropoietin-stimulating agent-naive, low-to-intermediate risk myelodysplastic syndrome patients through the initiation of our phase 3 COMMANDS study," said Backstrom.