New interim and subgroup results from the lidERA Phase 3 trial show giredestrant reduced invasive disease or death versus standard-of-care endocrine therapy across both premenopausal and postmenopausal groups in ER+/HER2− early breast cancer. The oral selective estrogen receptor degrader delivered hazard ratios of 0.65 in premenopausal patients and 0.74 in postmenopausal patients, with musculoskeletal-pain-driven discontinuations less frequent than on comparators. The findings position giredestrant as an adjuvant alternative to tamoxifen or aromatase inhibitor regimens, extending efficacy signal consistency by menopausal status while aiming to reduce treatment-limiting adverse events.