FDA Approval: Blinatumomab

On December 3, 2014, the FDA granted accelerated approval of blinatumomab (Blincyto; Amgen, Inc.) for treatment of Philadelphia chromosome-negative relapsed or refractory precursor B-cell acute lymphoblastic leukemia (R/R ALL). Blinatumomab is a recombinant murine protein that acts as a bispecific CD19-directed CD3 T-cell engager. The basis for the approval was a single-arm trial with 185 evaluable adults with R/R ALL. The complete remission (CR) rate was 32% 95% confidence interval (CI), 26%-40%, and the median duration of response was 6.7 months. A minimal residual disease response was achieved by 31% (95% CI, 25%-39%) of all patients. Cytokine release syndrome and neurologic events were serious toxicities that occurred. Other common (>20%) adverse reactions were pyrexia, headache, edema, febrile neutropenia, nausea, tremor, and rash. Neutropenia, thrombocytopenia, and elevated transaminases were the most common (>10%) laboratory abnormalities related to blinatumomab. A randomized trial is required in order to confirm clinical benefit.