Camizestrant (Etcamah – AstraZeneca), an oral estrogen receptor antagonist, has received accelerated approval from the FDA for use in combination with a cyclin-dependent kinase (CDK) 4/6 inhibitor for treatment of hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative, locally advanced or metastatic breast cancer in adults who have ESR1 mutations that were detected in circulating tumor DNA (ctDNA) during treatment with an aromatase inhibitor and a CDK 4/6 inhibitor.

Vepdegestrant (Veppanu – Rigel), an oral heterobifunctional protein degrader, has been approved by the FDA for treatment of estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative, estrogen receptor 1 (ESR1)-mutated advanced or metastatic breast cancer in adults who had disease progression following ≥1 prior line of endocrine therapy. It is the first proteolysis targeting chimera (PROTAC), a type of heterobifunctional protein degrader, to be approved in the US. The oral selective estrogen receptor degraders (SERDs) elacestrant (Orserdu) and imlunestrant (Inluriyo) were approved earlier for the same indication.

The FDA has approved imlunestrant (Inluriyo – Lilly), an oral estrogen receptor antagonist, for treatment of estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative, estrogen receptor 1 (ESR1)-mutated advanced or metastatic breast cancer in adults who had disease progression following at least one prior line of endocrine therapy. Imlunestrant is the second oral selective estrogen receptor degrader (SERD) to be approved in the US for treatment of breast cancer; elacestrant (Orserdu) was approved in 2023.