Antibody–Drug Conjugates and Small Molecule–Drug Conjugates: Opportunities and Challenges for the Development of Selective Anticancer Cytotoxic Agents

Conventional cancer chemotherapy heavily relies on the use of cytotoxic agents, which typically do not preferentially localize at the tumor site and cause toxicity to normal organs, preventing dose escalation to therapeutically active regimens. In principle, antibodies and other ligands could be used for the selective pharmacodelivery of cytotoxic agents to the neoplastic mass. For many years, the availability of ligands, capable of selective...