Blinatumomab

Blinatumomab is a bispecific T‑cell engager (BiTE) antibody used in the treatment of B-cell acute lymphoblastic leukemia (B-ALL). It binds CD19, a protein expressed on most B cells, and CD3, a component of the T-cell receptor, simultaneously. This dual binding redirects cytotoxic T cells to CD19-expressing B cells, promoting T-cell–mediated lysis and depletion of malignant B cells.

Indications include relapsed or refractory B-cell precursor ALL in adults and children, and B-ALL with minimal residual disease (MRD) positivity. It is approved in several jurisdictions for these settings and is often used to bridge to hematopoietic stem cell transplantation in eligible patients.

Administration is via continuous intravenous infusion, typically in 28-day cycles. Dosing uses a step-up approach to mitigate cytokine release syndrome and neurotoxicity: a lower daily dose (for example, 9 micrograms per day) for the first week, then a higher maintenance dose (commonly 28 micrograms per day) if tolerated. Infusion is delivered through a central venous catheter or implanted port, with a drug-free interval between cycles.

Common adverse events include cytokine release syndrome, neurologic events such as confusion or seizures, fever, infections, and cytopenias. The drug carries warnings for CRS and CNS events; patients require close monitoring, especially during the first cycle, and hospitalization is often recommended during initiation in many treatment settings. Infections and neutropenia are also considerations; discontinuation is required if severe toxicity occurs.

Brand name Blincyto; developed by Amgen. First approved by the FDA for relapsed or refractory B-ALL, with subsequent approvals expanding to MRD-positive B-ALL in select populations. Its use is typically as part of a multi-modality treatment plan, often bridging to stem cell transplantation when feasible.