Estrogen receptor alpha, also known as NR3A1, is one of two main types of estrogen receptor, a nuclear receptor that is activated by the sex hormone estrogen. In humans, ERα is encoded by the gene ESR1. From Wikipedia
Enrolling 624 previously treated patients at the American Society of Clinical Oncology meeting in Chicago, the trial delivered a more than three-month progression-free survival advantage over Faslodex, prompting Arvinas to cancel two other planned late-stage studies.