A review of blinatumomab, a novel immunotherapy

Blinatumomab is a novel bispecific CD19-directed CD3 T-cell engager recently approved for the treatment of relapsed or refractory Ph-negative acute lymphoblastic leukemia in adults. The drug was approved after a phase II trial in adults with relapsed/refractory disease demonstrated complete remission or hematologic complete remission in 43% of patients within two treatment cycles, of which 40% went on to receive an allogeneic hematopoietic stem cell transplant. In a long-term survival analysis of patients with minimal residual disease after chemotherapy, hematologic relapse-free survival was estimated at 61% at a median of 33 months after blinatumomab. Nine patients underwent hematopoietic stem cell transplant, and six patients remained in complete remission without hematopoietic stem cell transplant or further therapy. Limited data in relapsed pediatric acute lymphoblastic leukemia are reviewed. Blinatumomab carries boxed warnings for neurotoxicity and cytokine release syndrome, which may be serious and lead to treatment interruption and discontinuation. Clinical controversies with blinatumomab include use in patients with Ph-positive acute lymphoblastic leukemia, dosing in underweight adults, and the optimal management of cytokine release syndrome. Oncology pharmacists must be aware of detailed preparation and administration procedures required for safe use of blinatumomab. Clinical trials are ongoing in the first-line setting for patients with Ph-negative acute lymphoblastic leukemia, in Ph-positive acute lymphoblastic leukemia, and other B-cell malignancies.