Provided is a pharmaceutical polymer micelle composition showing a significantly enhanced effect compared with a drug (E7974) that is a hemiasterlin derivative. The pharmaceutical polymer micelle composition provided by the present invention carries E7974 represented by formula (i) and an antibody having a CDR sequence being the same as the CDR sequence of trastuzumab or cetuximab or a fragment of the antibody, each bonded thereto by a chemical bond. In this composition, E7974 is bonded to a side chain of a reducing aspartic acid group of a block copolymer constituting the polymer micelle, while the antibody or a fragment thereof is bonded to the free end side of a polyethylene glycol chain segment of another block copolymer.本發明提供一種與作為哈米特林(hemiasterlin)衍生物之一種的藥物(E7974)相比，顯著地顯示出效果增強之高分子微胞醫藥組成物。本發明提供一種高分子微胞醫藥組成物，其分別經由化學鍵搭載有下述式(i)所表示之E7974、具有與曲妥珠單抗(Trastuzumab)或西妥昔單抗(Cetuximab)所具有之CDR序列相同之CDR序列的抗體或者其片段。於該組成物中，E7974鍵結於構成高分子微胞之嵌段共聚物之還原型天冬胺酸殘基之側鏈，抗體或其片段鍵結於另一嵌段共聚物之聚乙二醇鏈段之自由端側。
