Definition

A radioimmunoconjugate consisting of the anti-CD22 monoclonal antibody epratuzumab chelated to the radioisotope yttrium-90 (Y 90). Yttrium Y 90 epratuzumab binds to tumor cells expressing CD22, delivering a cytotoxic dose of beta radiation. Epratuzumab is a humanized version of the murine monoclonal antibody LL2; CD22 is a B cell-restricted antigen present on the surfaces of mature B cells.