Biologic
UniProt P15391
Blinatumomab
Blincyto
- Mechanism of action
- Bispecific CD19/CD3 T-cell engager (BiTE)
- In plain language
- A two-armed protein that physically links a patient's own T cells to leukemia B cells, forcing the T cells to attack and kill the cancer cells directly.
- How it works
- Blinatumomab is a bispecific CD19-directed CD3 T-cell engager (BiTE) with a structural format distinct from a conventional antibody: rather than a four-chain, roughly 150-kDa immunoglobulin with an Fc region, it is a single ~54-kDa polypeptide chain composed of two tandem single-chain variable fragments — one binding CD19 on B-lineage cells, one binding CD3 on T cells — joined by a short flexible linker, with no Fc region present. By simultaneously engaging both targets, blinatumomab bridges a T cell and a CD19-positive B cell, forming an immunological synapse that activates the T cell independent of MHC-restricted antigen presentation, triggering cytolytic protein production and T-cell proliferation that result in redirected lysis of the target cell. Because it lacks an Fc region and the FcRn-mediated recycling that gives IgG-based antibodies serum half-lives measured in weeks, blinatumomab has a short serum half-life of approximately 2-3 hours and is administered as a continuous intravenous infusion rather than an intermittent dose.
- Therapeutic applications
- Per FDA-approved labeling, BLINCYTO (blinatumomab) is indicated for the treatment of adult and pediatric patients one month and older with CD19-positive B-cell precursor acute lymphoblastic leukemia (ALL) in first or second complete remission with minimal residual disease (MRD) greater than or equal to 0.1%; relapsed or refractory CD19-positive B-cell precursor ALL; or CD19-positive, Philadelphia chromosome-negative B-cell precursor ALL in the consolidation phase of multiphase chemotherapy.
- Class
- Bispecific antibody
- Therapeutic area
- Oncology (B-cell malignancies)
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