[{"from": "human", "value": "Could you give me a brief overview of this molecule? [C][C][C][=C][C][N][C][=Branch2][#Branch2][=N][=C][C][=C][Branch1][Branch1][C][Ring1][=Branch1][=O][C][O][C][=Branch1][C][=O][C@@][Ring1][=Branch2][Branch1][Ring1][C][C][O][C][=Branch1][C][=O][O][C][C][=C][C][=C][Branch1][Branch1][C][=C][Ring1][=Branch1][N][C][=Branch1][C][=O][C@H1][Branch1][Branch1][C][C][C][N][N][C][=Branch1][C][=O][C][O][C][C][=Branch1][C][=O][N][C][C][O][C][C][O][C][C][O][C][C][O][C][C][O][C][C][O][C][C][O][C][C][O][C][C][N][C][=C][Branch1][Branch1][N][=N][Ring1][Branch1][C][N][C][=Branch1][C][=O][C][C][C][C][Branch1][Branch1][C][C][Ring1][=Branch1][C][N][C][=Branch1][C][=O][C][C][Branch1][Branch1][C][Ring1][=Branch1][=O][S][C][C@@H1][Branch1][=Branch1][C][=Branch1][C][=O][O][N][C][Ring2][Branch2][Branch1][=N][C][=C][Ring2][Branch2][=Branch2][C][=C][Branch1][Branch1][C][=C][Ring1][=Branch1][O]"}, {"from": "gpt", "value": "The molecule is an antibody-drug conjugate (ADC) containing labetuzumab, a mildly reduced, anti-CEACAM5 humanized monoclonal antibody, conjugated to the potent topoisomerase I inhibitor SN-38, with antineoplastic activity.  The monoclonal antibody moiety of labetuzumab govitecan selectively binds to carcinoembryonic cell adhesion molecule 5 (CEACAM5), which is abundantly expressed on the surface of a majority of solid tumors. Upon internalization and proteolytic cleavage, SN-38, the active metabolite of irinotecan, inhibits the activity of topoisomerase I in the tumor cells, eventually inhibiting both DNA replication and transcription and leading to tumor cell apoptosis."}]