An object of the present invention is to provide a novel alkylating agent that specifically binds to an immune checkpoint gene to induce cell death, and has tumor-specific accumulating properties. The present invention provides a conjugate comprising an alkylating agent bonded to a polyamide that specifically binds to a gene encoding an immune checkpoint molecule, an alkylating agent specific for a gene encoding an immune checkpoint molecule, comprising the conjugate, and a pharmaceutical composition comprising the conjugate.
