Genentech’s Giredestrant Reduced Risk of Invasive Disease Recurrence or Death by 30% in ER-positive Early-Stage Breast Cancer

– Giredestrant is the only oral SERD to show superior invasive disease-free survival in the adjuvant setting, marking the first significant endocrine therapy advance in over 20 years –

– Transformational results support the potential of giredestrant to become a new standard-of-care for early-stage disease –

– ER-positive breast cancer accounts for approximately 70% of breast cancer cases, and up to a third experience recurrence on or after adjuvant endocrine therapy treatment –

– Data will be featured in an oral presentation at the 2025 San Antonio Breast Cancer Symposium and included in the official press program –

SOUTH SAN FRANCISCO, Calif.--(BUSINESS WIRE)--Genentech, a member of the Roche Group (SIX: RO, ROG; OTCQX: RHHBY), announced today positive data from the Phase III lidERA Breast Cancer study evaluating investigational giredestrant as an adjuvant endocrine treatment for people with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2-negative, early-stage breast cancer. At the pre-specified interim analysis, adjuvant giredestrant significantly reduced the risk of invasive disease recurrence or death by 30% (invasive disease-free survival [iDFS]) compared with standard-of-care endocrine therapy (SoC ET) (hazard ratio [HR]=0.70, 95% confidence interval [CI] 0.57-0.87, p=0.0014). The lidERA results are being presented at the 2025 San Antonio Breast Cancer Symposium and are included in the official press program.

“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, 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, and lidERA principal investigator. “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.”

“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,” said Levi Garraway, M.D., Ph.D., chief medical officer and head of Global Product Development. “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.”

At three years, 92.4% of patients in the giredestrant arm were alive and free of invasive disease versus 89.6% in the SoC ET arm. The iDFS benefit was consistent across all clinically relevant subgroups. Overall survival (OS) data were immature at the time of this analysis, but a clear positive trend was observed. Follow-up for OS will continue to the next analysis. 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. Giredestrant was well tolerated; adverse events were manageable and consistent with its known safety profile.

ER-positive breast cancer accounts for approximately 70% of breast cancer cases, and the majority are diagnosed in the early-stage. Currently, up to a third of people eventually experience recurrence on or after adjuvant endocrine therapy treatment for early-stage breast cancer. Additionally, many have to interrupt or stop treatment early due to safety or tolerability issues, thereby increasing the risk of death. These limitations underscore the need for more effective and better-tolerated options that can enhance adherence and prevent or delay disease recurrence.

Giredestrant is the first and only oral selective estrogen receptor degrader (SERD) to show superior iDFS in the adjuvant setting and lidERA is the second positive Phase III readout for giredestrant following the evERA Breast Cancer results in the metastatic setting. The scientific rationale for lidERA was supported by prior results in the neoadjuvant setting, including the coopERA trial showing that giredestrant was superior to an aromatase inhibitor in reducing malignant cell division (Ki67 levels). This growing body of evidence supports the potential of giredestrant to meaningfully improve outcomes compared with standard-of-care endocrine therapy across ER-positive early-stage and advanced breast cancer.

Genentech’s extensive giredestrant clinical development program spans multiple treatment settings and lines of therapy, reflecting our commitment to deliver innovative medicines to as many people with ER-positive breast cancer as possible.

About the lidERA Breast Cancer study

lidERA Breast Cancer [NCT04961996] is a Phase III, randomized, open-label, multicenter study evaluating the efficacy and safety of adjuvant giredestrant versus standard-of-care endocrine therapy in people with medium- or high-risk stage I-III estrogen receptor-positive, human epidermal growth factor receptor 2-negative breast cancer. Over 4,100 patients were enrolled in the study.

The primary endpoint is invasive disease-free survival (iDFS) excluding unrelated cancers in other organs (second primary non-breast cancers). Key secondary endpoints include overall survival, iDFS including second primary non-breast cancers, disease-free survival and safety.

About giredestrant

Giredestrant is an investigational, oral, next-generation selective estrogen receptor degrader (SERD) and full antagonist.

Giredestrant is designed to block estrogen from binding to the estrogen receptor, triggering its breakdown (known as degradation) and stopping or slowing down the growth of cancer cells.

Giredestrant has an extensive clinical development program and is being investigated in five company-sponsored Phase III clinical trials that span multiple treatment settings and lines of therapy to benefit as many people as possible:

• Giredestrant versus standard-of-care endocrine therapy (SoC ET) as adjuvant treatment in estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative early-stage breast cancer (lidERA Breast Cancer; NCT04961996)
• Giredestrant plus everolimus versus SoC ET plus everolimus in ER-positive, HER2-negative, locally advanced or metastatic breast cancer (evERA Breast Cancer; NCT05306340)
• Giredestrant plus palbociclib versus letrozole plus palbociclib in ER-positive, HER2-negative, endocrine-sensitive, recurrent locally advanced or metastatic breast cancer (persevERA Breast Cancer; NCT04546009)
• Giredestrant plus investigator’s choice of a cyclin-dependent kinase 4/6 (CDK-4/6) inhibitor versus fulvestrant plus a CDK4/6 inhibitor in ER-positive, HER2-negative advanced breast cancer resistant to adjuvant endocrine therapy (pionERA Breast Cancer; NCT06065748)
• Giredestrant plus dual HER2 blockade versus dual HER2 blockade in ER-positive, HER2-positive locally advanced or metastatic breast cancer (heredERA Breast Cancer; NCT05296798)

About estrogen receptor (ER)-positive breast cancer

Globally, the burden of breast cancer continues to grow, with 2.3 million women diagnosed and 670,000 dying from the disease every year. Breast cancer remains the number one cause of cancer-related deaths amongst women, and the second most common cancer type.

ER-positive breast cancer accounts for approximately 70% of breast cancer cases. A defining feature of ER-positive breast cancer is that its tumor cells have receptors that attach to estrogen, which can contribute to tumor growth.

Despite treatment advances, ER-positive breast cancer remains particularly challenging to treat due to its biological complexity. Patients often face the risk of disease progression, treatment side effects and resistance to endocrine therapy. There is an urgent need for more effective treatments that can delay clinical progression and reduce the burden of treatment on people’s lives.

About Genentech in Breast Cancer

Genentech has been advancing breast cancer research for more than 30 years with the goal of helping as many people with the disease as possible. Our medicines, along with companion diagnostic tests, have contributed to bringing breakthrough outcomes in multiple types of breast cancers. As our understanding of breast cancer biology rapidly improves, we are working to identify new biomarkers and approaches to treatment for other subtypes of the disease, including estrogen receptor-positive breast cancer, which is a form of hormone receptor-positive breast cancer, the most prevalent type of all breast cancers.

About Genentech

Founded nearly 50 years ago, Genentech is a leading biotechnology company that discovers, develops, manufactures and commercializes medicines to treat patients with serious and life-threatening medical conditions. The company, a member of the Roche Group, has headquarters in South San Francisco, California. For additional information about the company, please visit http://www.gene.com.