CD37

Class

Antibody-drug conjugate (anti-CD37 humanized mAb naratuximab/K7153B conjugated via Multilink linker to a DM1 maytansinoid payload)

CD37 is a cell-surface protein belonging to the tetraspanin family, expressed predominantly on mature B lymphocytes, including many malignant B cells found in lymphomas and certain leukemias. Because its expression is largely restricted to this cell lineage, CD37 serves as a docking point for antibody-drug conjugates (ADCs), a therapeutic format that pairs a targeting antibody with a cytotoxic payload. In this design, a humanized monoclonal antibody recognizes CD37 on the surface of B cells and, after binding, is drawn into the cell through a process called internalization. Once inside, a chemical linker connecting the antibody to a potent microtubule-disrupting agent (a maytansinoid) is processed, releasing the payload so it can interfere with cell division and trigger cell death. This targeted delivery strategy aims to concentrate cytotoxic activity within CD37-expressing tumor cells while sparing tissues that lack the receptor, in contrast to conventional chemotherapy, which acts broadly on dividing cells throughout the body. The approach is relevant across B-cell malignancies, particularly non-Hodgkin lymphomas, where CD37 is often retained even when other B-cell markers are lost or downregulated, offering an alternative or complementary antigen for therapeutic targeting.