# ESR1 in breast cancer

3 EU-approved indications in breast cancer need a ESR1 result: camizestrant (1st line, advanced), elacestrant (2nd line, advanced) and imlunestrant (2nd line, advanced).

## Approved indications

### ESR1 mutation

| Drug | Biomarker requirement | Regimen | Setting | Conditions |
|---|---|---|---|---|
| [Camizestrant](https://oncolabels.com/drugs/camizestrant) (Etcamah) | ESR1 mutation, ER-positive, HER2-negative | + a CDK4/6 inhibitor (palbociclib, ribociclib, or abemaciclib) | 1st line, advanced | During first-line endocrine therapy + CDK4/6 inhibitor, before progression; In pre- or peri-menopausal women and in men, should be combined with a LHRH agonist or antagonist |
| [Elacestrant](https://oncolabels.com/drugs/elacestrant) (Orserdu) | ESR1 mutation, ER-positive, HER2-negative | Monotherapy | 2nd line, advanced | After at least one line of endocrine therapy including a CDK 4/6 inhibitor; Postmenopausal women, and men |
| [Imlunestrant](https://oncolabels.com/drugs/imlunestrant) (Inluriyo) | ESR1 mutation, ER-positive, HER2-negative | Monotherapy | 2nd line, advanced | After prior treatment with an endocrine based regimen; In pre- or perimenopausal women, or men, Inluriyo should be combined with a luteinising hormone-releasing hormone (LHRH) agonist |

## Label wording

- **Camizestrant** (Etcamah), Breast cancer, 1st line, advanced: “Etcamah in combination with a CDK4/6 inhibitor (palbociclib, ribociclib, or abemaciclib) is indicated for the treatment of adult patients with ER-positive, HER2-negative, locally advanced or metastatic breast cancer upon detection of ESR1-mutation and without disease progression during first-line endocrine therapy in combination with a CDK4/6 inhibitor (for biomarker based patient-selection, see section 4.2 and 5.1).” [SmPC](https://www.ema.europa.eu/en/documents/product-information/etcamah-epar-product-information_en.pdf)
- **Elacestrant** (Orserdu), Breast cancer, 2nd line, advanced: “ORSERDU monotherapy is indicated for the treatment of postmenopausal women, and men, with estrogen receptor (ER)-positive, HER2-negative, locally advanced or metastatic breast cancer with an activating ESR1 mutation who have disease progression following at least one line of endocrine therapy including a CDK 4/6 inhibitor.” [SmPC](https://www.ema.europa.eu/en/documents/product-information/orserdu-epar-product-information_en.pdf)
- **Imlunestrant** (Inluriyo), Breast cancer, 2nd line, advanced: “Inluriyo is indicated as monotherapy for the treatment of adult patients with oestrogen receptor (ER)-positive, HER2-negative, locally advanced or metastatic breast cancer with an activating ESR1-mutation, who have disease progression following prior treatment with an endocrine based regimen (for biomarker-based patient selection, see section 4.2).” [SmPC](https://www.ema.europa.eu/en/documents/product-information/inluriyo-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/breast-cancer/esr1