[(S)-1-[[(S)-1-[[4-(羟甲基)苯基]氨基]-1-氧代-5-脲基戊烷-2-基]氨基]-3-甲基-1-氧代丁-2-基]氨基甲酸(9H-芴-9-基)甲酯

抗体-药物结合物（ADC）由理想的单克隆抗体、活性细胞毒性药物和合适的连接剂组成。抗体和细胞毒性药物之间的适当连接物提供特异性桥，从而帮助抗体选择性地将细胞毒性药物递送至肿瘤细胞，并在肿瘤部位精确地释放细胞毒性药物；The list of ADCs in the clinic continues to grow, bolstered by the success of first two marketed ADCs: ADCETRIS® and Kadcyla®. Currently, there are 40 ADCs in various phases of clinical development. However, only 34 of these have published their structures. Of the 34 disclosed structures, 24 of them use a linkage to the thiol of cysteines on the monoclonal antibody. The remaining 10 candidates utilize chemistry to surface lysines of the antibody. Due to the inherent heterogeneity of conjugation to the multiple lysines or cysteines found in mAbs, significant research efforts are now being directed toward the production of discrete, homogeneous ADC products, via site-specific conjugation. These site-specific conjugations may involve genetic engineering of the mAb to introduce discrete, available cysteines or non-natural amino acids with an orthogonally-reactive functional group handle such as an aldehyde, ketone, azido, or alkynyl tag. These site-specific approaches not only increase the homogeneity of ADCs but also enable novel bio-orthogonal chemistries that utilize reactive moieties other than thiol or amine. This broadens the diversity of linkers that can be utilized which will lead to better linker design in future generations of ADCs.