ertumaxomab ertumaxomab ertumaxomab (trade name rexomun) is a rat-murine hybrid monoclonal antibody designed to treat some types of cancer. ertumaxomabmonoclonal antibodytypetrifunctional antibodysourcerat/mouse hybridtargether2/neu, cd3clinical datatrade namesrexomunatc codenoneidentifierscas number509077-99-0 nchemspidernoneuniil5l45ygp1o ny (what is this?) (verify) it is a trifunctional antibody which works by linking t-lymphocytes and macrophages to the cancer cells. phase ii clinical trial evaluating the treatment of breast cancer was terminated due to change in fresenius' development plans. (so they could concentrate on their other product catumaxomab (trade name removab).: 35 )