Antibody-drug conjugates (ADCs)
A monoclonal antibody carries a potent cytotoxic drug straight to cancer cells that display its target, such as HER2, CD30, Nectin-4 or TROP-2.
What they are
Antibody-drug conjugates join three parts: an antibody against a protein found on the tumour surface, a chemical linker and a cytotoxic «payload» too toxic to give on its own. Examples: trastuzumab emtansine and trastuzumab deruxtecan (HER2), brentuximab vedotin (CD30), enfortumab vedotin (Nectin-4) and sacituzumab govitecan (TROP-2). All are given intravenously.
Mechanism of action
The antibody binds its antigen, the complex is taken into the cell by endocytosis and broken down in lysosomes, and the payload is released inside the cancer cell. Two payload families dominate: microtubule poisons (emtansine/DM1, monomethyl auristatin E or MMAE) cause mitotic arrest, and topoisomerase I inhibitors (deruxtecan, SN-38) cause DNA damage. Toxicity comes from both the payload (cytopenias, neuropathy) and the target (for example HER2 in the heart).
Target: Tumour surface antigens (HER2, CD30, Nectin-4, TROP-2) plus the payload's target (microtubules or topoisomerase I)
Drugs in this class
- Gemtuzumab ozogamicinAn anti-CD33 antibody carrying calicheamicin, a DNA-cutting toxin; used in CD33-positive acute myeloid leukaemia…CD33 (SIGLEC3) on myeloid leukaemia cells
- Inotuzumab ozogamicinAn anti-CD22 antibody carrying calicheamicin; used in relapsed or refractory B-cell acute lymphoblastic leukaemia…CD22 on B-lymphoblasts
- Trastuzumab deruxtecanAnti-HER2 antibody carrying a topoisomerase I inhibitor; used in HER2-positive and HER2-low breast cancer and other…HER2 (ErbB2) receptor on tumour cells
- Trastuzumab emtansineTrastuzumab joined to the microtubule poison DM1; used in HER2-positive breast cancer. Watch the liver, the heart and…HER2 (ErbB2) receptor on tumour cells
- Brentuximab vedotinAnti-CD30 antibody carrying the microtubule poison MMAE; used in Hodgkin and anaplastic large cell lymphoma. Watch for…CD30 (TNFRSF8) on lymphoma cells
- Enfortumab vedotinAnti-Nectin-4 antibody carrying MMAE, for advanced urothelial (bladder) cancer, often with pembrolizumab. Watch skin…Nectin-4, a cell adhesion protein on urothelial cancer cells
- Sacituzumab govitecanAnti-TROP-2 antibody carrying SN-38, the active form of irinotecan; used in advanced breast cancer. Boxed risks…TROP-2 (TACSTD2), a surface protein of many epithelial cancers
Others in the class
- gemtuzumab ozogamicin
- polatuzumab vedotin
- belantamab mafodotin
- tisotumab vedotin
- datopotamab deruxtecan
- mirvetuximab soravtansine
Test yourself
Think of the answer, then tap the question to see it.
What are the three parts of an antibody-drug conjugate?
An antibody against a tumour surface antigen, a linker and a cytotoxic payload.
What does the «vedotin» ending tell you about the payload?
It is monomethyl auristatin E (MMAE), a microtubule-disrupting agent.
Which two ADCs carry a topoisomerase I inhibitor?
Trastuzumab deruxtecan (deruxtecan) and sacituzumab govitecan (SN-38).
Why can trastuzumab emtansine cause heart failure?
Its antibody blocks HER2, which is also needed by heart muscle, as with plain trastuzumab.
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Fam-Trastuzumab Deruxtecan-nxki - NCI (National Cancer Institute, 2026); Ado-Trastuzumab Emtansine - NCI (National Cancer Institute, 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
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Representative model, for educational purposes only.