SOUTH SAN FRANCISCO, CA — December 10, 2025 — Leads & Copy —
Genentech, a member of the Roche Group, has reported positive data from its Phase III lidERA Breast Cancer study. The study evaluated the investigational drug giredestrant as an adjuvant endocrine treatment for individuals with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative, early-stage breast cancer.
The interim analysis, pre-specified in the study design, showed that adjuvant giredestrant significantly reduced the risk of invasive disease recurrence or death by 30% (invasive disease-free survival [iDFS]) compared to standard-of-care endocrine therapy (SoC ET). The hazard ratio (HR) was 0.70, with a 95% confidence interval (CI) of 0.57-0.87, and a p-value of 0.0014. The results were presented at the 2025 San Antonio Breast Cancer Symposium.
Dr. Aditya Bardia, M.D., M.P.H., director of the breast oncology program and professor of medicine at the David Geffen School of Medicine at University of California, Los Angeles (UCLA), and director of translational research integration at the UCLA Health Jonsson Comprehensive Cancer Center, served as the lidERA principal investigator. Dr. Bardia highlighted the urgent need for more effective and tolerable endocrine therapies due to challenges with disease recurrence and treatment adherence in early ER-positive breast cancer.
According to Dr. Bardia, giredestrant is the first new medicine in almost 25 years to demonstrate superiority over existing endocrine therapies in the curative setting, suggesting its potential as a new standard-of-care endocrine therapy for breast cancer patients.
Levi Garraway, M.D., Ph.D., chief medical officer and head of Global Product Development, emphasized the substantial efficacy of giredestrant and its potential to become a new standard-of-care endocrine therapy in ER-positive early-stage breast cancer. The company aims to share these results with health authorities globally to expedite the availability of this new treatment option to patients.
The study found that at three years, 92.4% of patients in the giredestrant arm were alive and free of invasive disease, compared to 89.6% in the SoC ET arm. The iDFS benefit remained consistent across all clinically relevant subgroups. While overall survival (OS) data were not yet mature at the time of analysis, a positive trend was observed, and follow-up for OS will continue. Giredestrant also demonstrated a 31% risk reduction of distant recurrence-free interval (HR=0.69, 95% CI 0.54-0.89), another key secondary endpoint. The drug was well-tolerated, with manageable adverse events consistent with its known safety profile.
ER-positive breast cancer accounts for approximately 70% of breast cancer cases, with the majority diagnosed at an early stage. Up to a third of people eventually experience recurrence on or after adjuvant endocrine therapy, and many interrupt or stop treatment early due to safety or tolerability issues, which increases the risk of death.
The lidERA Breast Cancer study is a Phase III, randomized, open-label, multicenter study that enrolled over 4,100 patients with medium- or high-risk stage I-III estrogen receptor-positive, human epidermal growth factor receptor 2-negative breast cancer. The primary endpoint of the study is invasive disease-free survival (iDFS) excluding unrelated cancers in other organs. Key secondary endpoints include overall survival, iDFS including second primary non-breast cancers, disease-free survival, and safety.
Genentech is also investigating giredestrant in several other Phase III clinical trials, including the evERA Breast Cancer study in ER-positive, HER2-negative, locally advanced or metastatic breast cancer (NCT05306340); the persevERA Breast Cancer study in ER-positive, HER2-negative, endocrine-sensitive, recurrent locally advanced or metastatic breast cancer (NCT04546009); the pionERA Breast Cancer study in ER-positive, HER2-negative advanced breast cancer resistant to adjuvant endocrine therapy (NCT06065748); and the heredERA Breast Cancer study in ER-positive, HER2-positive locally advanced or metastatic breast cancer (NCT05296798).
Founded nearly 50 years ago, Genentech is a biotechnology company that discovers, develops, manufactures and commercializes medicines for serious and life-threatening medical conditions and is a member of the Roche Group.
Contact:
Aditya Bardia, M.D., M.P.H., director, breast oncology program, professor of medicine at the David Geffen School of Medicine at University of California, Los Angeles (UCLA), director of translational research integration at the UCLA Health Jonsson Comprehensive Cancer Center
Levi Garraway, M.D., Ph.D., chief medical officer and head of Global Product Development
Source: Genentech
