Dalotuzumab (MK-0646) is a recombinant humanized IgG1 monoclonal antibody that specifically targets the insulin-like growth factor 1 receptor (IGF-1R). its mechanism of action involves the inhibition of IGF-mediated oncogenic signaling, which subsequently induces apoptosis and cell cycle arrest in tumor cells, and it has demonstrated enhanced antitumor efficacy when used in combination with other chemotherapeutic agents.