Why are antibody-drug conjugates used in HER2-targeted therapy?

An antibody-drug conjugate has three parts: an antibody, a linker and a drug payload. The antibody attaches to HER2 on a cancer cell. The cell can then take in the conjugate, where the linker is processed and the payload can interfere with cell growth or division. This combines a recognition step with a treatment effect. HER2 levels and the cancer’s wider features help the oncology team decide whether this approach fits; it is not suitable for every tumour or every person.

Ask which HER2 test supports the treatment choice, how the medicine will be given and how often monitoring is needed. Keep an up-to-date list of medicines and report heart problems, lung conditions, allergies or pregnancy concerns before treatment. During therapy, record symptoms such as nausea, diarrhoea, tiredness, rash, infusion reactions or changes in breathing. Do not stop treatment without discussing concerns with the oncology team, because timing and monitoring are part of safe use.

Tell the treatment team promptly about new or worsening breathlessness, swelling, chest discomfort, a fast or irregular heartbeat, fever, severe diarrhoea, persistent vomiting or a reaction during or soon after an infusion. Seek emergency help for severe breathing difficulty, collapse or chest pain. The team may need to assess whether symptoms relate to treatment, infection or another cause.

What does my HER2 test show? What payload does this conjugate carry? How will heart and lung health be monitored? Which symptoms should be reported immediately, and what alternatives could be considered if this treatment is unsuitable?