floxuridine + gemcitabine hydrochloride + yttrium Y 90 anti-CEA monoclonal antibody cT84.66

This is an experimental combination therapy consisting of three agents: - **Floxuridine** (a pyrimidine analog antimetabolite chemotherapeutic), - **Gemcitabine hydrochloride** (a nucleoside analog used as a chemotherapeutic and radiosensitizer), - **Yttrium Y 90 anti-CEA monoclonal antibody cT84.66** (a chimeric human/murine IgG1 monoclonal antibody targeting carcinoembryonic antigen [CEA], radiolabeled with the beta-emitter yttrium-90). The combination is designed for the treatment of advanced, CEA-expressing solid tumors, including colorectal cancer and non-small cell lung cancer. The mechanism involves: - Direct cytotoxicity from floxuridine and gemcitabine, - Radiosensitization by gemcitabine to enhance the effect of radioimmunotherapy, - Targeted delivery of beta radiation via the anti-CEA antibody conjugated to yttrium Y 90, which binds specifically to CEA-overexpressing tumor cells, delivering localized radiation while sparing normal tissue. The cT84.66 antibody was developed at City of Hope and has high affinity for CEA with minimal cross-reactivity to normal tissues[1][6][7]. This approach aims to maximize tumor cell kill through synergistic mechanisms—chemotherapy-induced DNA damage, radiosensitization, and targeted radiotherapy[1][6].