The present invention provides heterocyclic linker compounds useful for linking drug moieties to ligands. The compounds also include drug-ligand conjugates comprising a ligand capable of targeting a selected cell population, and a drug connected to the ligand by a heterocyclic linker moiety. The linker moiety comprises a peptide sequence that is a substrate for an intracellular enzyme, for example a cathepsin, that cleaves the peptide at an amide bond. The peptide further contains a self-immolating moiety which connects the drug and the protein peptide sequence. Upon cleavage of the peptide sequence by an intracellular enzyme the self-immolating moiety cleaves itself from the drug moiety such that the drug moiety is in an underivatized and active form.
本发明提供了用于将药物基团连接到
配体的杂环连接物。这些化合物还包括药物-
配体共轭物,包括一个能够靶向特定细胞群的
配体,以及通过杂环连接基团与
配体连接的药物。连接基团包括一个肽序列,该肽序列是细胞内酶的底物,例如一种半胱
氨酸
蛋白酶,它在酰胺键处切割肽。肽进一步包含连接药物和蛋白质肽序列的自解放基团。通过细胞内酶切割肽序列,自解放基团从药物基团中解离,使得药物基团处于未衍生和活性形式。