BASEL, Switzerland — October 1, 2026

Roche announced detailed results from the Phase III evERA Breast Cancer study evaluating investigational giredestrant in combination with everolimus in people with ER-positive, HER2-negative locally advanced or metastatic breast cancer following treatment with a CDK4/6 inhibitor and endocrine therapy. The combination significantly improved progression-free survival (PFS) compared with standard endocrine therapy plus everolimus. In the intent-to-treat population, median PFS was 8.8 months with giredestrant plus everolimus versus 5.5 months with the comparator arm, corresponding to a 44% reduction in the risk of disease progression or death (HR 0.56; p<0.001). In the ESR1-mutated population, median PFS was 10.0 months versus 5.5 months, representing a 62% reduction in risk (HR 0.38; p<0.001).

Giredestrant Shows Greater Benefit in ESR1-Mutated Disease

The evERA results showed consistent PFS improvement across the overall and ESR1-mutated populations. Overall survival data remained immature at the time of analysis, although Roche reported a positive trend in both populations. The safety profile of the giredestrant combination was generally manageable and consistent with the known safety profiles of the individual medicines, with no unexpected safety findings reported. Additional analyses presented at the 2026 American Society of Clinical Oncology Annual Meeting also indicated improvements in PFS2 and chemotherapy-free survival compared with standard endocrine therapy, suggesting potential benefit beyond the initial progression endpoint.

Giredestrant Targets Endocrine Therapy Resistance

Giredestrant is an investigational oral selective estrogen receptor degrader (SERD) designed to block estrogen signaling and promote degradation of the estrogen receptor. The evERA study focuses on patients whose disease has progressed following treatment with a CDK4/6 inhibitor and endocrine therapy, a setting where acquired resistance to endocrine treatment can contribute to further disease progression. ESR1 mutations are found in a substantial proportion of ER-positive disease after CDK inhibitor treatment and can contribute to endocrine resistance. By directly targeting the estrogen receptor, giredestrant is being developed as a potential oral treatment option for patients with advanced hormone receptor-positive breast cancer.

Advertisement

cGxPJobs Banner

Roche Advances Giredestrant Across Multiple Breast Cancer Settings

Giredestrant is being evaluated across an extensive Phase III development program covering early and advanced breast cancer. The program includes lidERA, evaluating giredestrant as adjuvant therapy in early-stage ER-positive, HER2-negative breast cancer; evERA, evaluating the combination with everolimus in advanced disease; as well as persevERA, pionERA and heredERA studies across additional treatment settings. The FDA has set PDUFA goal dates of November 30, 2026 for giredestrant in early-stage breast cancer and December 18, 2026 for its application in advanced disease. Giredestrant remains investigational, and regulatory review is ongoing. The evERA findings add Phase III evidence supporting continued evaluation of the oral SERD in patients with ER-positive advanced breast cancer.

Source: Roche, press release