Roche announced positive phase III results from the lidERA Breast Cancer study evaluating giredestrant as an adjuvant endocrine treatment for oestrogen receptor-positive, HER2-negative, early-stage breast cancer. The study met its primary endpoint, showing a statistically significant improvement in invasive disease-free survival with giredestrant versus standard-of-care endocrine therapy.
This is the first phase III trial of a selective oestrogen receptor degrader to demonstrate a benefit in the adjuvant setting. The majority of breast cancer cases are diagnosed at an early stage.
“Today’s results underscore the potential of giredestrant as a new endocrine therapy of choice for people with early-stage breast cancer, where there is a chance for cure,” said Dr. Levi Garraway, Roche’s Chief Medical Officer and Head of Global Product Development. “Given that ER-positive breast cancer accounts for approximately 70% of cases diagnosed, these findings – together with recent data in the advanced ER-positive setting – suggest that giredestrant has the potential to improve outcomes for many people with this disease.”
Overall survival data were immature at the time of interim analysis, but a positive trend was observed. Giredestrant was well tolerated with no unexpected safety findings. Data will be presented at an upcoming medical meeting and shared with health authorities.
ER-positive breast cancer accounts for approximately 70% of breast cancer cases. Up to a third of people experience recurrence on or after adjuvant endocrine therapy treatment for early-stage breast cancer. Many patients interrupt or stop treatment early due to safety or tolerability issues.
The lidERA study is the second positive phase III readout for giredestrant following evERA Breast Cancer, which was presented at the European Society for Medical Oncology Congress 2025.
Giredestrant is an investigational, oral selective oestrogen receptor degrader designed to block oestrogen from binding to the oestrogen receptor, triggering its breakdown and stopping or slowing the growth of cancer cells.
The lidERA study enrolled over 4,100 patients with medium- or high-risk stage I-III oestrogen receptor-positive, HER2-negative breast cancer. The primary endpoint is invasive disease-free survival excluding unrelated cancers.
Roche is investigating giredestrant in five phase III clinical trials spanning multiple treatment settings and lines of therapy. The trials include adjuvant treatment in early-stage breast cancer, combination with everolimus in advanced breast cancer, combination with palbociclib in endocrine-sensitive recurrent breast cancer, and combination with CDK4/6 inhibitors in treatment-resistant advanced breast cancer.
Globally, 2.3 million women are diagnosed with breast cancer and 670,000 die from the disease annually.
