Roche released detailed phase 3 data showing its oral selective estrogen receptor degrader, giredestrant, improved progression-free survival across patients with ER-positive, HER2-negative breast cancer, including those without ESR1 mutations. Results presented at ESMO demonstrated a 44% PFS improvement in the intention-to-treat population and a 62% improvement in the ESR1-mutated cohort, strengthening Roche’s positioning against injectable SERDs and other endocrine options. Investigators presented both efficacy and subgroup analyses at the European Society for Medical Oncology meeting; Charles Fuchs, Roche’s head of oncology development, framed the drug as intended for “all comers.” The filings and labeling pathway remain dependent on overall survival follow-up and regulator assessment of benefit across subgroups. The data could reshape second-line endocrine strategies and affect uptake of competing SERDs and CDK4/6 inhibitor-combination regimens if regulators grant approvals consistent with the ESMO readouts.