NEJM publishes Genentech evERA Phase III: giredestrant plus everolimus delays progression in ER+ advanced breast cancer

On 1 October 2026, Genentech (Roche Group) announced that detailed results from the Phase III evERA Breast Cancer study of investigational giredestrant plus everolimus were published in the New England Journal of Medicine. The open-label randomized multicenter trial (NCT05306340) compared the combination with standard endocrine therapy plus everolimus in people with ER-positive, HER2-negative locally advanced or metastatic breast cancer after prior CDK4/6 inhibitor and endocrine therapy.

Key efficacy numbers (company / NEJM announcement)

In the ESR1-mutated population, median progression-free survival (PFS) was 10.0 months with giredestrant plus everolimus versus 5.5 months in the comparator arm (stratified HR=0.38, 95% CI 0.27–0.54, p<0.001) — about a 62% reduction in risk of progression or death as framed in the release. In the intent-to-treat (ITT) population, median PFS was 8.8 versus 5.5 months (HR=0.56, 95% CI 0.44–0.71, p<0.001) — about a 44% risk reduction. Overall survival data were immature, with a reported positive trend (ITT HR=0.69, 95% CI 0.47–1.00; ESR1-mutated HR=0.62, 95% CI 0.38–1.02). Adverse events were described as manageable and consistent with known profiles; no unexpected safety findings, including no photopsia and low bradycardia rates, the company said.

Regulatory context and limits

Based on evERA, the FDA accepted an NDA for giredestrant plus everolimus in ESR1-mutated advanced disease with a goal date of 18 December 2026; a Priority Review NDA for adjuvant early-stage disease (lidERA) has a PDUFA date of 30 November 2026. Giredestrant remains investigational pending decisions. This summarises a Phase III open-label randomized trial publication announcement — not personal medical advice; patients should consult their oncology team.