LMB-70

LMB-70 is a recombinant immunotoxin (RIT) targeting B-cell maturation antigen (BCMA), developed by the National Cancer Institute (NCI). It is composed of an anti-BCMA antibody Fab fragment fused to a 24-kDa fragment of Pseudomonas Exotoxin A (PE), specifically domain III. The agent is designed to treat multiple myeloma by binding to BCMA on the surface of malignant B cells. Following internalization, the toxin moiety catalyzes the ADP-ribosylation of elongation factor 2 (EF-2), which halts protein synthesis and leads to apoptotic cell death. Preclinical studies in mouse models of bone marrow myeloma have demonstrated that LMB-70 can induce complete and durable remissions without significant toxicity.