Bound polymer compound and use thereof in camptothecin derivatives and hsp90 inhibitors

And efficiently deliver two agents to the affected area, the side effects is reduced, the polymer compound enhancing the efficacy is provided, and to provide an antitumor agent that it as an active ingredient. Polymer compound is one that camptothecin derivative to a carboxyl group in the side chain of the block copolymer of polyethylene glycol segments and polyglutamate segments are linked with the HSP90 inhibitor has an ester bond.