Definition

A radioimmunoconjugate of the humanized IgG1 monoclonal antibody (MoAb) LL2 labeled with Technetium 99m (Tc-99m). Epratuzumab (MoAb LL2) recognizes CD22, a B-lymphocyte-restricted antigen expressed as a cytoplasmic protein in progenitor B cells, and as a cell surface protein in mature B cells. Tc-99m epratuzumab delivers gamma emission Tc-99m directly to B-lymphocyte lineage cells, thereby the agent may be used for diagnostic or treatment purposes.