BASILIXIMAB IS A CHIMERIC MURINE/HUMAN MONOCLONAL ANTIBODY SIMILAR TO DACLIZUMAB THAT FUNCTIONS AS AN INTERLEUKIN-2 RECEPTOR ANTAGONIST BY BINDING TO THE ALPHA CHAIN (CD25 ANTIGEN) OF THE INTERLEUKIN-2 RECEPTOR ON THE SURFACE OF ACTIVATED T-LYMPHOCYTES. BASILIXIMAB IS SPECIFICALLY TARGETED AGAINST IL-2RA, WHICH IS SELECTIVELY EXPRESSED ON THE SURFACE OF ACTIVATED T-LYMPHOCYTES. THIS SPECIFIC HIGH AFFINITY BINDING OF BASILIXIMAB TO IL-2RA COMPETITIVELY INHIBITS IL-2-MEDIATED ACTIVATION OF LYMPHOCYTES, A CRITICAL PATHWAY IN THE CELLULAR IMMUNE RESPONSE INVOLVED IN ALLOGRAFT REJECTION. WHILE IN THE CIRCULATION, BASILIXIMAB IMPAIRS THE RESPONSE OF THE IMMUNE SYSTEM TO ANTIGENIC CHALLENGES. IT IS USED IN THE PREVENTION OF ACUTE GRAFT REJECTION EPISODES IN PATIENTS UNDERGOING RENAL TRANSPLANTATION, AND IS GIVEN AS PART OF AN IMMUNOSUPPRESSIVE REGIMEN THAT INCLUDES CICLOSPORIN AND CORTICOSTEROIDS; AZATHIOPRINE OR MYCOPHENOLATE MOFETIL MAY ALSO BE ADDED TO THE REGIMEN.