Racotumomab is a therapeutic anti-idiotype monoclonal antibody vaccine. It mimics the structure of Neu5Gc-GM3 ganglioside, a tumor-associated antigen expressed on various cancer cells (e.g., melanoma, breast, lung). The vaccine stimulates the patient's immune system to produce antibodies against this antigen, aiming to induce an anti-tumor immune response. It has been studied primarily in advanced non-small cell lung cancer.