# HER2 in triple-negative breast cancer

2 EU-approved indications in triple-negative breast cancer need a HER2 result: trastuzumab deruxtecan (2nd line, advanced) and datopotamab deruxtecan (1st line, advanced).

## Approved indications

### HER2-low

| Drug | Biomarker requirement | Regimen | Setting | Conditions |
|---|---|---|---|---|
| [Trastuzumab deruxtecan](https://oncolabels.com/drugs/trastuzumab-deruxtecan) (Enhertu) | IHC 1+ or IHC 2+/ISH-negative, HER2-low | Monotherapy | 2nd line, advanced | After prior chemotherapy in the metastatic setting or disease recurrence during or within 6 months of completing adjuvant chemotherapy |

### ER/PR/HER2 negative

| Drug | Biomarker requirement | Regimen | Setting | Conditions |
|---|---|---|---|---|
| [Datopotamab deruxtecan](https://oncolabels.com/drugs/datopotamab-deruxtecan) (Datroway) | Triple-negative (ER-negative, PR-negative, HER2-negative) | Monotherapy | 1st line, advanced | Not candidates for PD-1/PD-L1 inhibitor therapy |

## Tumour-agnostic approvals

Approved for any solid tumour that carries the alteration, wherever the tumour started.

### HER2

| Drug | Biomarker requirement | Regimen | Setting | Conditions |
|---|---|---|---|---|
| [Trastuzumab deruxtecan](https://oncolabels.com/drugs/trastuzumab-deruxtecan) (Enhertu) | HER2-positive (IHC 3+) | Monotherapy | 2nd line, advanced | After prior treatment; No satisfactory treatment options |

## Label wording

- **Trastuzumab deruxtecan** (Enhertu), Breast cancer, 2nd line, advanced: “• HER2-low breast cancer who have received prior chemotherapy in the metastatic setting or developed disease recurrence during or within 6 months of completing adjuvant chemotherapy (see section 4.2).” [SmPC](https://www.ema.europa.eu/en/documents/product-information/enhertu-epar-product-information_en.pdf)
- **Datopotamab deruxtecan** (Datroway), Triple-negative breast cancer, 1st line, advanced: “Datroway as monotherapy is indicated for the first-line treatment of adult patients with unresectable or metastatic triple-negative breast cancer (TNBC) who are not candidates for PD-1/PD-L1 inhibitor therapy (see section 5.1).” [SmPC](https://www.ema.europa.eu/en/documents/product-information/datroway-epar-product-information_en.pdf)

Source: section 4.1 of each summary of product characteristics (SmPC), EMA data as of 5 Nov 2026. AI models structured these entries and no person has checked them yet. oncolabels is a non-commercial reference for education and research and gives no medical advice; the current SmPC takes precedence.

Data under CC BY 4.0: credit oncolabels and the European Medicines Agency. Page: https://oncolabels.com/tumours/triple-negative-breast-cancer/her2