Roche’s Giredestrant Shows Significant Progression-Free Survival Benefit in Phase III ER-Positive Breast Cancer Trial

Roche has announced positive results from the Phase III evERA study evaluating giredestrant combined with everolimus in patients with estrogen receptor (ER)-positive, HER2-negative, locally advanced or metastatic breast cancer. These patients had previously been treated with CDK 4/6 inhibitors and endocrine therapy. The study met both co-primary endpoints, showing a statistically significant and clinically meaningful improvement in progression-free survival (PFS) in both the overall intention-to-treat group and the ESR1-mutated population, compared to standard-of-care endocrine therapy plus everolimus.

While overall survival (OS) data remain immature, the study observed a clear positive trend, with follow-up ongoing for the next OS analysis. The giredestrant combination was well tolerated, and adverse events were consistent with the known safety profiles of the individual treatments, with no new safety concerns identified. This marks the first positive head-to-head Phase III trial comparing an all-oral selective estrogen receptor degrader regimen against a standard-of-care combination.

Levi Garraway, Roche’s Chief Medical Officer and Head of Global Product Development, highlighted that the giredestrant combination offers meaningful benefits for ER-positive breast cancer patients whose disease progressed after CDK inhibitor treatment. Roche plans to engage with regulatory authorities to bring this regimen to patients with advanced ER-positive breast cancer as soon as possible.

ER-positive breast cancer represents around 70% of breast cancer cases and remains challenging to treat due to its biological complexity. Resistance to endocrine therapies, particularly after CDK inhibitor treatment, increases the risk of progression and poor outcomes. The combination of giredestrant and everolimus targets two different signaling pathways, potentially improving patient outcomes. Its all-oral administration may also reduce treatment burden by eliminating the need for injections.

Roche’s broad giredestrant clinical development program spans multiple treatment settings, underlining the company’s commitment to advancing innovative therapies for ER-positive breast cancer. Data from the evERA study will be submitted to health authorities with the goal of making this new treatment option available promptly.