# Living with an antibody-drug conjugate: diarrhoea, blood counts, eyes and lungs

Source: https://onco.cc/terms/adc-side-effects-breast/  
OnCo record `adc-side-effects-breast` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

The antibody-drug conjugates used in triple-negative breast cancer carry chemotherapy into the cancer but still cause chemotherapy-like effects: sacituzumab govitecan mainly low white cells and diarrhoea, datopotamab deruxtecan mouth soreness, eye problems and rarely lung inflammation, trastuzumab deruxtecan lung inflammation and sickness. Each has a threshold for ringing the 24-hour line.

## Summary

Macmillan says sacituzumab govitecan is given on days 1 and 8 of a 21-day cycle, that it can cause severe diarrhoea, and to contact the hospital straight away on the 24-hour number for diarrhoea 4 or more times in a day, diarrhoea at night, or anti-diarrhoea drugs not working within 24 hours, as well as for a temperature above 37.5 C or below 36 C. Breast Cancer Now uses 3 or more times in 24 hours and says growth factor injections are sometimes recommended to protect white cells. The Datroway label requires eye examinations and lists keratitis; the Enhertu label carries a boxed warning for interstitial lung disease, and a pooled analysis found 15.4% of people on trastuzumab deruxtecan developed drug-related lung inflammation, most within the first year. This is orientation from public patient pages and guidelines, not advice for your case: your own team's instructions and 24-hour number come first.

## Fields

- Kind: Term
- Last checked: 2026-09-24
- Also known as: ADC side effects

## Sources

- Macmillan: sacituzumab govitecan: https://www.macmillan.org.uk/cancer-information-and-support/treatments-and-drugs/sacituzumab-govitecan
- Breast Cancer Now: sacituzumab govitecan (Trodelvy): https://breastcancernow.org/about-breast-cancer/treatment/targeted-therapy/sacituzumab-govitecan-trodelvy
- Macmillan: antibody drug conjugate treatment: https://www.macmillan.org.uk/cancer-information-and-support/treatments-and-drugs/antibody-drug-conjugate
- Powell et al., pooled analysis of interstitial lung disease in nine trastuzumab deruxtecan studies (ESMO Open 2022): https://doi.org/10.1016/j.esmoop.2022.100554
- Bardia et al., sacituzumab govitecan in metastatic triple-negative breast cancer, ASCENT (NEJM 2021): https://doi.org/10.1056/NEJMoa2028485

## Connected records

- cancers: [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- technologies: [Antibody-drug conjugate (ADC)](https://onco.cc/technologies/adc/)
- drugs: [Datopotamab deruxtecan](https://onco.cc/drugs/datopotamab-deruxtecan/), [Sacituzumab govitecan](https://onco.cc/drugs/sacituzumab-govitecan/), [Trastuzumab deruxtecan](https://onco.cc/drugs/trastuzumab-deruxtecan/)
- terms: [Interstitial lung disease (ILD) / pneumonitis](https://onco.cc/terms/ild/), [Neutropenia](https://onco.cc/terms/neutropenia/), [Ocular toxicity (keratopathy, blurred vision)](https://onco.cc/terms/ocular-toxicity/)

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