Tucotuzumab celmoleukin is a fusion protein consisting in a humanized monoclonal antibody and an interleukin-2 factor. The humanized monoclonal antibody of this drug is tucotuzumab, which can recognize and bind to the epithelial cell adhesion molecule (EpCAM or KS), a cell surface epithelial protein expressed in a variety of cancer cells. The interleukin-2 drug partially coupled with the antibody is celmoleukin, which can stimulate the anti-tumor immune response of cytotoxic T cells. The drug was developed by EMD Pharmaceuticals and has been used in the treatment of ovarian cancer and small cell lung cancer.