Cytotoxic payload intracellular target

Cytotoxic payload intracellular target is a descriptive term rather than a specific biological entity, referring to the intracellular molecules or structures targeted by the toxic moiety (payload) of an antibody-drug conjugate (ADC) or similar delivery system (Nature Reviews Drug Discovery). While the antibody component provides specificity by binding to a cell-surface antigen, the payload is responsible for the cytotoxic effect once internalized and released into the cytoplasm or nucleus (Journal of Hematology & Oncology). Common intracellular targets include tubulin, which is inhibited by antimitotic agents like auristatins (e.g., MMAE) and maytansinoids (e.g., DM1), leading to cell cycle arrest in the G2/M phase (PubChem). Other payloads target DNA directly, such as calicheamicins which cause double-strand breaks, or inhibit enzymes like Topoisomerase I (e.g., SN-38, DXd), which prevents DNA ligation and induces apoptosis (NIH/NCI). Because this term encompasses a wide variety of distinct molecular targets (enzymes, structural proteins, and nucleic acids), it is considered a functional category in pharmacology rather than a single therapeutic target (Wikipedia). The selection of an appropriate intracellular target is a critical design parameter in ADC development, as it dictates the drug's potency and its potential for dose-limiting toxicities.

Other names

ADC payload targetCytotoxic warhead targetIntracellular payload targetWarhead target

Inhibition of microtubule polymerization, DNA strand breakage, or inhibition of Topoisomerase I activity following intracellular release.