B43-genistein immunoconjugate

B43-genistein immunoconjugate is a novel therapeutic agent that combines the targeting ability of a monoclonal antibody with the cytotoxic effects of a tyrosine kinase inhibitor. It was developed primarily for treating B-lineage leukemias and lymphomas, particularly those expressing the CD19 antigen. The immunoconjugate consists of the murine monoclonal anti-CD19 antibody B43 conjugated to genistein, a naturally occurring tyrosine kinase inhibitor derived from soybeans. This conjugation allows for targeted delivery of genistein to CD19-positive malignant cells, triggering apoptotic cell death by inhibiting tyrosine kinases associated with cell growth and survival pathways. Clinical trials have shown that B43-genistein has favorable pharmacokinetics with a plasma half-life of approximately 20 hours. It has demonstrated some clinical efficacy in heavily pretreated patients with B-lineage acute lymphoblastic leukemia, with one durable complete remission and two transient responses reported in early trials. The immunoconjugate specifically targets the membrane-associated anti-apoptotic CD19-LYN complexes in malignant B cells. By delivering genistein directly to these complexes, it can induce selective apoptosis in CD19-positive cells while minimizing systemic toxicity. Development of this agent represented the first effort to produce a clinical-grade genistein immunoconjugate for treatment of B-lineage leukemia and lymphoma, and the first clinical pharmacokinetics study of a tyrosine kinase inhibitor-containing immunoconjugate. Despite showing promise in early clinical development, B43-genistein appears to have been discontinued for further development in cancer indications.

Other names

B43 (anti-CD19)-genisteinanti-CD19-genisteinanti-CD-19-genisteinanti-CD 19-genistein