BIIB019,DAC HYP Daclizumab is a humanized IgG1 monoclonal antibody that binds to human interleukin 2 receptor (anti-Tac or anti-CD25)and composed of human >90%) and murine (10%) antibody sequences. The human sequence is derived from the constant domain of human IgG1 and the variable framework region of Eu myeloma antibody. The murine part was taken from the complementarity-determining regions of a murine anti-Tac antibody. Daclizumab has been used for preventing acute organ rejection in de novo allogeneic kidney transplantation when used simultaneously with immunosuppressive regimens such as cyclosporine and corticosteroid and in the treatment of adult patients with relapsing multiple sclerosis. These trademarks were Zenapax and Zimbryta, respectively.