Therapeutic Response Statement (Sensitivity)

This therapeutic response statement supports the relationship that ER positive, ESR1 activating variants, HER2-negative status confers therapeutic sensitivity to Imlunestrant in patients with Invasive Breast Carcinoma.

The European Medicines Agency (EMA) has authorized imlunestrant as a monotherapy for the treatment of adult patients with estrogen 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. The EPAR notes that in pre- or perimenopausal women, or men, imlunestrant should be combined with a luteinising hormone-releasing hormone (LHRH) agonist. Furthermore, it notes that patients should be selected based on the presence of an activating ESR1-variant in tumor or in plasma specimens, using a CE-marked in vitro diagnostic with the corresponding intended purpose or an alternative validated test.

This statement is based on a regulatory approval from the European Medicines Agency:

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.

Citation

Eli Lilly Nederland B.V. Inluriyo (imlunestrant) [product information]. European Medicines Agency website. https://www.ema.europa.eu/en/documents/product-information/inluriyo-epar-product-information_en.pdf. Revised February 2026. Accessed May 5, 2026.