Roche: Giredestrant plus Everolimus Extended Progression-Free Survival in Advanced Breast Cancer

Swiss pharmaceutical company Roche has published detailed Phase III results from its evERA Breast Cancer study in The New England Journal of Medicine. The study found that the investigational drug giredestrant, when combined with everolimus, significantly improved progression-free survival (PFS) compared to standard endocrine therapy plus everolimus. This was observed in patients with estrogen receptor-positive (ER-positive) locally advanced or metastatic breast cancer whose disease had progressed or recurred following treatment with a cyclin-dependent kinase (CDK)4/6 inhibitor and endocrine therapy.

The combination of giredestrant and everolimus reduced the risk of disease progression or death by 44% in the overall patient population (ITT) and by 62% in the subgroup with ESR1 mutations. The median PFS was 8.8 months in the ITT population and 10.0 months in the ESR1-mutated population, compared to 5.5 months in the control group.

Data on overall survival (OS) were immature at the time of analysis, though a positive trend was noted. Adverse events associated with the combination were manageable and consistent with the known safety profiles of the individual drugs. The U.S. Food and Drug Administration (FDA) is expected to make decisions on the new drug applications in late November and December 2026.

Roche previously reported positive findings from the lidERA study in early-stage breast cancer, reinforcing the potential of giredestrant to redefine care standards for both metastatic and early-stage disease. ER-positive, HER2-negative breast cancer accounts for approximately 70% of all breast cancer cases, and resistance to endocrine therapies presents a significant clinical challenge.