S16 Ep1: Targeted Therapies Take Center Stage for Estrogen Receptor–Positive Breast Cancer: With Aditya Bardia, MD, MPH, FASCO

Aditya Bardia, MD, MPH, FASCO, evaluates the shifting treatment landscape for HR-positive, HER2-negative breast cancer, highlighting the Phase III lidERA study results. This trial demonstrates that the novel oral selective estrogen receptor degrader (SERD) giredestrant reduces the risk of recurrence or death by 30% compared to standard endocrine therapy in early-stage disease, while also showing improved tolerability. The ongoing Phase III INAVO123 trial explores the triplet of inavolisib, a CDK4/6 inhibitor, and letrozole as a first-line treatment for PIK3CA-mutated metastatic disease, aiming to expand precision medicine into the endocrine-sensitive setting. Personalized therapy remains a central theme, driven by the development of next-generation endocrine agents, novel combinations including AKT and CDK2 inhibitors, and the increasing role of antibody-drug conjugates like T-DXd and sacituzumab govitecan. Consistent genomic testing for actionable mutations such as ESR1 and PIK3CA is essential for optimizing these genotype-directed therapies.