ABI793 is a human IgG1 anti-CD154 (CD40 ligand) monoclonal antibody. It inhibits immune responses by blocking the CD154-CD40 (IC50= 75 nM) signaling pathway. ABI793 is effective in preventing kidney transplant rejection and can be used in research related to immune rejection responses.

ABI793 inhibits the binding of CD154 and CD40 in a concentration-dependent manner, with an IC50 of 75 nM. For four days, ABI793 suppresses IL-4 stimulated B cell proliferation, with an IC50 of 73 nM. Over a period of five days, it also inhibits the human mixed lymphocyte reaction (MLR), with an IC50 of 320 ng/mL.

Administering ABI793 (20 mg/kg, intravenously, on postoperative days 0, 1, 4, 11, 18, 28, 56, and 84) significantly extended the survival of transplanted kidneys in crab-eating macaques and effectively prevented transplant rejection. The compound also notably prolonged the survival time of renal transplants in rhesus monkeys.