Blinatumomab
BlincytoUniProt P15391 · 3D model
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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 small, engineered protein built like a bridge with a hook on each end. One hook grabs onto CD19, a marker found on B cells, including leukemia cells; the other hook grabs onto CD3, a marker found on T cells, the immune cells that kill abnormal cells. By holding both cell types close together, it forces the T cell to attack and destroy the leukemia cell directly. Most antibody drugs are large, four-part molecules that circulate in the blood for weeks; blinatumomab is a single, much smaller chain, so it's cleared from the body within hours rather than weeks — which is why it's delivered continuously through an IV pump, often worn by the patient, over days to weeks at a time.
What it’s used for
Blinatumomab is approved to treat a type of blood cancer called B-cell precursor acute lymphoblastic leukemia (ALL) in patients one month of age and older — when a small trace of leukemia remains detectable after initial treatment, when the leukemia has come back or didn't respond to earlier treatment, or as part of a multi-step chemotherapy plan for certain patients.
- Mechanism
- Bispecific CD19/CD3 T-cell engager (BiTE)
- Drug class
- Bispecific antibody
- Therapeutic area
- Oncology (B-cell malignancies)
The antibody engineered to physically wire a T cell to its target
Most antibody drugs have two identical arms that grab the same target. Blinatumomab is built differently: one arm grabs a marker on leukemia cells, and the other arm grabs a killer T cell, physically wiring the two together so the T cell attacks the cancer cell it's now stuck to. It was the first drug of this two-armed "bispecific" design ever approved, and the engineering trick it pioneered, forcing an immune cell into direct contact with a cancer cell, has since been copied by many other cancer drugs.
Pivotal trial
A single-arm, multicenter phase 2 trial in adults with relapsed or refractory B-precursor ALL, in which 43% of patients achieved complete remission or complete remission with partial hematologic recovery within two treatment cycles.