Cixutumumab (also known as IMC-A12) is an investigational fully human monoclonal antibody that was developed as a targeted therapy for cancer. It functions by inhibiting the activity of a key receptor involved in cell growth, proliferation, and survival. Clinical trials evaluated its efficacy, both as a monotherapy and in combination with other agents (such as chemotherapy or targeted therapies), for a range of solid tumors, including sarcomas, prostate cancer, colorectal cancer, and non-small cell lung cancer (NSCLC). Despite promising preclinical data, its clinical development was ultimately discontinued as later-phase trials did not demonstrate sufficient improvement in overall survival to support regulatory approval.