The invention provides novel cytotoxic compounds and cytotoxic conjugates comprising these cytotoxic compounds and cell-binding agents. More specifically, this invention relates to novel thailanstatin A analogs, useful as cytotoxic small molecule toxins in antibody-drug conjugates (ADCs). The present invention further relates to compositions including these cytotoxic compounds and ADCs, and methods for using these toxins and ADCs to treat pathological conditions including cancer.本發明提供新穎細胞毒性化合物及包含該等細胞毒性化合物及細胞結合劑之細胞毒性偶聯物。更具體而言，本發明係關於新穎泰蘭他汀A (thailanstatin A)類似物，其可在抗體-藥物偶聯物(ADC)中用作細胞毒性小分子毒素。本發明進一步係關於包括該等細胞毒性化合物及ADC之組合物，及使用該等毒素及ADC治療包括癌症在內之病理學病況之方法。
