Sotatercept (ACE-011) for the treatment of chemotherapy-induced anemia in patients with metastatic breast cancer or advanced or metastatic solid tumors treated with platinum-based chemotherapeutic regimens: results from two phase 2 studies

PURPOSE: Sotatercept may represent a novel approach to the treatment of chemotherapy-induced anemia (CIA). We report the results from two phase 2 randomized studies examining the use of sotatercept for the treatment of CIA in patients with metastatic cancer. METHODS: In study A011-08, patients with metastatic breast cancer were randomized to 2:2:2:1 to receive sotatercept 0.1, 0.3, or 0.5 mg/kg, or placebo, respectively, every 28 days. In study ACE-011-NSCL-001, patients with solid tumors treated with platinum-based chemotherapy received sotatercept 15 or 30 mg every 42 days. The primary endpoint for both studies was hematopoietic response, defined as a hemoglobin (Hb) increase of ≥1 g/dL from baseline. RESULTS: Both studies were terminated early due to slow patient accrual. Among patients treated with sotatercept in the A011-08 and ACE-011-NSCL-001 studies, more patients achieved a mean Hb increase of ≥1 g/dL in the combined sotatercept 0.3 mg/kg and 15 mg (66.7 %) group and sotatercept 0.5 mg/kg and 30 mg (38.9 %) group versus the sotatercept 0.1 mg/kg (0 %) group. No patients achieved a mean Hb increase of ≥1 g/dL in the placebo group. The incidence of treatment-related adverse events (AEs) was low in both studies, and treatment discontinuations due to AEs were uncommon. CONCLUSIONS: Although both studies were terminated early, these results indicate that sotatercept is active and has an acceptable safety profile in the treatment of CIA.