Acceleron Pharma Inc. (NASDAQ:XLRN), a clinical stage biopharmaceutical company focused on the discovery, development and commercialization of novel protein therapeutics for cancer and rare diseases, today announced that its collaboration partner Celgene reported new interim data at the 55 th American Society of Hematology (ASH) Annual Meeting of sotatercept in patients with beta-thalassemia. Interim data presented from the ongoing phase 2 trial demonstrate dose dependent increases in hemoglobin in non-transfusion dependent beta-thalassemia patients. Beta-thalassemia is a genetic hematologic disorder causing chronic and life-threatening anemia and serious complications affecting the spleen, liver and heart.
The data were presented in a poster session by Maria Domenica Cappellini, M.D., University of Milan, Milan, Italy, an investigator of the phase 2 clinical trial. The presentation included new interim data from the 0.5 mg/kg dose level as well as longer term clinical data from patients in the 0.1 mg/kg and 0.3 mg/kg dose levels in the ongoing trial. The phase 2 clinical trial is an open label, dose escalation study designed to determine a safe and effective dose of sotatercept administered subcutaneously every three weeks in adult patients with beta-thalassemia. A total of twenty-five patients were enrolled in the first three dose cohorts; eight in the 0.1 mg/kg cohort, nine in the 0.3 mg/kg cohort, and eight in the 0.5 mg/kg cohort. Eighteen patients have non-transfusion dependent beta-thalassemia and seven patients have transfusion dependent beta-thalassemia. The phase 2 trial is ongoing and currently enrolling patients at a dose level of 0.75 mg/kg to determine a safe and effective dose range for the pivotal trial.
The poster containing these data is available on the Acceleron website under the Publications section.
Sotatercept Clinical Data Overview
- Dose dependent increases in hemoglobin were observed across the three dose levels evaluated
- Within the first two months of receiving the first dose of sotatercept:
- 84% of non-transfusion dependent patients in each of the 0.5 and 0.3 mg/kg dose levels achieved at least a 1 g/dL increase in hemoglobin, while none of the non-transfusion dependent patients at the lowest dose level (0.1 mg/kg) achieved this threshold
- 33%, 16% and 0% of non-transfusion dependent patients achieved a hemoglobin increase of at least 2 g/dL in the 0.5, 0.3, and 0.1 mg/kg dose levels, respectively
- Five of six non-transfusion dependent patients treated at the 0.3 mg/kg dose level had a sustained increase in hemoglobin through at least 10 cycles of treatment (3 weeks per cycle)
- A statistically significant relationship (p<0.001) between drug exposure and maximum increase in hemoglobin during the first three cycles was demonstrated across the three dose levels tested
- Sotatercept was generally safe and well tolerated in patients at all dose levels evaluated