Switch to a SERD Before Clinical Progression in ESR1-Mutated Advanced Breast Cancer?

For patients with advanced breast cancer who acquire ESR1 mutations during first-line AI and CDK4/6 inhibitor therapy, switching to camizestrant — before disease progression — improves PFS.

In early trials, camizestrant, a next-generation selective estrogen receptor degrader (SERD) and complete ER antagonist, demonstrated activity in patients with ESR1-mutated breast cancer. A strategy to change systemic therapy based on molecular evolution of the cancer before clinical evidence of progression has been considered a means to improve survival, but not yet convincingly proven.

In the industry-funded, phase 3 SERENA-6 trial, nearly 3300 patients with ER+/ HER2− advanced breast cancer who had received at least 6 months of first-line treatment with an aromatase inhibitor (AI) plus a CDK4/6 inhibitor, and did not have evidence of disease progression, underwent testing for ESR1 mutations in circulating tumor DNA every 2 to 3 months. Ul…

Reviewing Author

William J. Gradishar, MD

Disclosures

Consultant/Advisory BoardLilly; AstraZeneca; Gilead

Grant/Research SupportBreast Cancer Research Foundation

Editorial BoardsClinical Breast Cancer; Oncology; Annals of Surgery; Breast Cancer Research and Treatment

Leadership Positions in Professional SocietiesNational Comprehensive Cancer Network (Chair, Breast Cancer Panel); American Board of Internal Medicine (Medical Oncology Board)