FDA approves Blincyto for Ph- ALL-Onyx Pharma/Amgen

The FDA has granted approval of Blincyto (blinatumomab), from Onyx Pharma/Amgen, for the treatment of patients with Philadelphia chromosome-negative (Ph-) relapsed or refractory B-cell precursor Acute Lymphoblastic Leukemia (ALL). This indication is approved under accelerated approval. Continued approval for this indication may be contingent upon verification of clinical benefit in subsequent trials. With this approval, Blincyto becomes the first FDA-approved bispecific CD19-directed CD3 T-cell engager (BiTE) antibody construct product, and the first single-agent immunotherapy to be approved for the treatment of patients with Ph- relapsed or refractory B-cell precursor ALL.

The approval is based on results of Amgen's '211 trial, a Phase II, multicenter, single-arm open-label study. Eligible patients were under 18 years of age with Ph- relapsed or refractory B-cell precursor ALL. Relapsed or refractory was defined as relapsed with first remission duration of over 12 months in the first salvage, or relapsed or refractory after first salvage therapy, or relapsed within 12 months of allogeneic hematopoietic stem cell transplantation, and had more than 10 percent blasts in bone marrow. Of the 185 patients evaluated in the trial, 41.6 percent achieved complete remission or complete remission with partial hematologic recovery (CR/CRh*) within two cycles of treatment with Blincyto, which was the primary endpoint of the study. The majority of responses (81 percent) occurred within the first cycle of treatment. Among patients who achieved CR/CRh*, 39 percent went on to HSCT, and 75.3 percent achieved minimal residual disease response, a measure of eradication of residual disease at the molecular level.