An immunotoxin is an artificial protein consisting of a targeting portion linked to a toxin.
They were originally produced by attaching the antibody to the toxin using a chemical linker.
The best clinical success has been achieved in treating patients with refractory hairy cell leukemia.
In two uncontrolled clinical studies, about half of participants achieved a complete response after BL22 treatment.
A recent Phase I study of Resimmune found an 89% response rate in a subgroup of nine patients with cutaneous T cell lymphoma.