Roche has announced positive results from its phase III evERA study, evaluating investigational giredestrant in combination with everolimus for people with oestrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative, locally advanced or metastatic breast cancer who had previously received both a CDK4/6 inhibitor and endocrine therapy.
The study met both co-primary endpoints, demonstrating a statistically significant and clinically meaningful improvement in progression-free survival (PFS) in both the intention-to-treat and ESR1-mutated populations, compared with standard-of-care endocrine therapy plus everolimus.
Although overall survival (OS) data remain immature, a clear positive trend was observed, and follow-up will continue for the next OS analysis. The giredestrant combination was well tolerated, with adverse events consistent with the known safety profiles of the individual therapies, and no new safety signals identified.
This marks the first positive head-to-head phase III trial investigating an all-oral selective oestrogen receptor degrader (SERD)-containing regimen against a standard of care combination.
“These results show that the giredestrant combination provided a meaningful benefit for ER-positive breast cancer patients whose disease has progressed following treatment with a CDK inhibitor,” said Levi Garraway, Roche’s Chief Medical Officer and Head of Global Product Development. “We look forward to discussing these results with regulatory authorities with the goal of making this giredestrant-based regimen available to many people with advanced ER-positive breast cancer.”
ER-positive breast cancer represents about 70% of all breast cancer cases. Despite treatment advances, it remains difficult to treat due to its biological complexity. Resistance to endocrine therapies, particularly in the post-CDK inhibitor setting, increases the risk of progression and is associated with poor outcomes.
Combination therapies such as giredestrant plus everolimus may address this challenge by targeting two different signaling pathways, potentially leading to improved outcomes. Additionally, being an all-oral regimen, the combination could help reduce the treatment burden by avoiding injections.
Roche’s broad giredestrant development program spans multiple treatment settings and therapy lines, underscoring its commitment to expanding treatment options for people with ER-positive breast cancer.
Data from the evERA study will be submitted to health authorities to support potential approval and availability for patients.