Swiss healthcare MNC Roche’s experimental breast cancer drug giredestrant has delivered a major win, slashing the risk of invasive disease recurrence or death by 30% in a pivotal phase III trial, the company has announced.

 

New results from the lidERA Breast Cancer study — unveiled at the 2025 San Antonio Breast Cancer Symposium — show that the oral selective oestrogen receptor degrader (SERD) outperformed standard-of-care endocrine therapy in people with oestrogen receptor (ER)-positive, HER2-negative early-stage breast cancer.

 

At the trial’s pre-specified interim analysis, giredestrant achieved a hazard ratio of 0.70, marking a statistically significant improvement in invasive disease-free survival.

 

“In early ER-positive breast cancer, challenges with disease recurrence and treatment adherence mean there is an urgent need for more effective, tolerable endocrine therapies,” said Aditya Bardia, Director of the Breast Oncology Program at UCLA and principal investigator of lidERA. 

 

“After almost 25 years, a new medicine – giredestrant – has demonstrated superiority over existing endocrine therapies in the curative setting, highlighting its potential as a new standard-of-care endocrine therapy for patients with breast cancer.”

 

Levi Garraway, Roche’s Chief Medical Officer, added: “The substantial efficacy observed with giredestrant in the lidERA trial underscores its potential to become a new standard-of-care endocrine therapy in ER-positive early-stage breast cancer, where the chance for cure is highest. We look forward to sharing these results with health authorities around the world with the aim of bringing this new treatment option to patients as soon as possible.”

 

The data offer a compelling signal: after three years, 92.4% of patients on giredestrant were alive and free of invasive disease, compared with 89.6% on standard therapy. The benefit was consistent across clinically relevant subgroups.

 

Although overall survival data remain immature, researchers reported a clear positive trend. Giredestrant also cut the risk of distant recurrence by 31%, another key secondary endpoint. Safety findings were in line with earlier studies, and side effects were manageable.

 

ER-positive breast cancer accounts for roughly 70% of cases worldwide, most diagnosed at an early stage. Yet up to a third of patients still relapse despite endocrine therapy, and many struggle to stay on treatment due to tolerability issues — a gap giredestrant is designed to fill.

 

The drug is the first and only oral SERD to show superior invasive disease-free survival in the adjuvant setting, and lidERA marks its second positive phase III readout, following metastatic results from the evERA trial. Earlier neoadjuvant data — including the coopERA study showing sharp reductions in Ki67 levels — further bolster its potential.

 

Roche says its broad giredestrant programme spans “multiple treatment settings and lines of therapy,” underscoring the company's push to expand options for people with ER-positive disease.

 

lidERA Breast Cancer is a global phase III, randomised, open-label trial comparing adjuvant giredestrant with standard endocrine therapy in more than 4,100 people with medium- or high-risk stage I–III ER-positive, HER2-negative breast cancer. The primary endpoint is invasive disease-free survival excluding unrelated secondary cancers; key secondary endpoints include overall survival, disease-free survival and safety.