Definition

A combination agent composed of two humanized monoclonal antibodies, PSB102, an Fc-enhanced immunoglobulin G1 (IgG1) monoclonal antibody directed against the human B-cell-specific cell surface antigen and tumor-associated antigen (TAA) CD20, and PSB107, an IgG1 monoclonal antibody directed against the TAA CD37, with potential immunomodulating and antineoplastic activities. Upon administration, anti-CD20/CD37 monoclonal antibody combination PSB202 specifically targets and binds to CD20 and CD37 expressed on tumor cells. This induces antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) against CD20- and CD37-expressing B cells, which leads to B-cell apoptosis and the inhibition of tumor cell proliferation. CD20, a non-glycosylated cell surface phosphoprotein that is exclusively expressed on B cells during most stages of B-cell development, is often overexpressed in B-cell malignancies. CD37, a member of the tetraspanin superfamily of cell surface antigens, is overexpressed on a variety of cancer cell types and plays a key role in tumor cell proliferation.