ESR1 and breast cancer: Additionally, the SERENA-2 trial demonstrated the efficacy of camizestrant, a next-generation selective estrogen receptor degrader (ngSERD), in patients with advanced HR+ HER2- BC who had progressed or relapsed after ≤1 line of ET and ≤1 line of CHT in the advanced setting, without prior exposure to fulvestrant or other SERDs.