Phase 2 Trial Results Suggest Luspatercept Is Effective in Treating Myelodysplastic Syndrome

Treating myelodysplastic syndrome (MDS) patients with luspatercept can increase hemoglobin and decrease the burden of red blood cell (RBC) transfusion for more than 26 months, according to new results from a phase 2 trial.

Acceleron Pharma recently presented their phase 2 study results at the 22nd Congress of the European Hematology Association in Madrid, Spain. The trial included 88 lower-risk MDS patients that were treated with therapeutic doses of luspatercept, a modified activin receptor type IIB fusion protein.

Of the 88 participants, 50% reached a clinically significant erythroid response—an increase of hemoglobin or a decrease in RBC transfusion burden—while 38% (23 of 60 patients with ≥2 units RBC / 8 weeks transfusion burden at baseline) reached RBC transfusion independence for 8 or more weeks. The trial also revealed a significant increase in hemoglobin for up to 26 months for patients with a low transfusion burden.

“This Phase 2 update further supports our confidence that luspatercept could become a potential first-in-class treatment for lower-risk MDS patients. With some patients continuing on study for more than 26 months, we are very encouraged by both the durability of response and safety profile of luspatercept,” said Habib Dable, president and chief executive officer of Acceleron. “With Phase 3 trials across two indications ongoing and new studies planned, we and Celgene remain committed to exploring the full opportunity for luspatercept to transform patients’ lives.”

The majority of adverse effects from the treatment were grade 1 or 2 and included headache, fatigue, hypertension, bone pain, diarrhea, arthralgia, injection site erythema, myalgia, and edema peripheral.

“The longer term results of these Phase 2 studies reinforce the potential of inhibiting ligands in the TGF-beta superfamily for patients with lower-risk MDS,” said Michael Pehl, president of hematology/oncology for Celgene. “With the Phase 3 study now fully enrolled, we look forward to advancing luspatercept as part of our ongoing commitment to individuals with MDS around the world.”

The phase 3 study, called the MEDALIST trial, will investigate the effectiveness of luspatercept in lower-risk MDS patients who require RBC transfusions. Results from MEDALIST are expected to be available in 2018.