Provided are a pharmaceutical composition containing: (i) an antibody-drug conjugate comprising a drug linker represented by the following formula (wherein A indicates the position of the bond with the antibody) and an antibody bonded by a thioether bond； (ii) a histidine buffer； (iii) sucrose or trehalose； and (iv) a surfactant； as well as a lyophilization method for said pharmaceutical composition.一種醫藥組成物，其包含(i)由下式(式中，A表示與抗體的結合位置)所示之藥物連接子(linker)與抗體藉由硫醚鍵而結合之抗體-藥物結合物(conjugate)、(ii)組胺酸緩衝劑、(iii)蔗糖或海藻糖、及(iv)界面活性劑；以及該醫藥組成物的冷凍乾燥方法。
