Monoclonal antibodies are laboratory-produced, infection-fighting proteins that can locate and attach to cancer cells wherever they are in the body. Injected intravenously, monoclonal antibodies circulate through the bloodstream until they find cancer cells with the target antigen. The antibodies then bind to the cancer cells and signal other immune cells to help destroy or contain the tumor.

Monoclonal antibodies can be used alone or as a vehicle for delivering lethal doses of radiation, chemotherapy, or other toxins directly to the tumor.

Monoclonal antibody therapies, including treatment for advanced melanoma, are currently being investigated in clinical trials. Phase III randomized trials for the treatment of breast cancer and colorectal cancer have compared the effectiveness of standard chemotherapy delivered by monoclonal antibodies to standard chemotherapy treatment. Results suggest that monoclonal antibody therapy improves response to treatment, as well as disease-free and overall survival.^1,2