Roche has announced positive results from the phase III evERA study evaluating its investigational oral selective oestrogen receptor degrader (SERD), giredestrant, in combination with everolimus in people with oestrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative, locally advanced or metastatic breast cancer.

All participants had previously received treatment with a cyclin-dependent kinase (CDK) 4/6 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 positive trend was observed, with further follow-up ongoing. The giredestrant combination was well tolerated and adverse events were consistent with the known safety profiles of the individual study treatments, and no new safety signals were reported.

This marks the first positive head-to-head phase III trial investigating an all-oral selective oestrogen receptor degrader-containing regimen versus 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,” he added.  

ER-positive breast cancer accounts for approximately 70 percent of breast cancer cases. A defining feature of this type of breast cancer is that its tumour cells have receptors that attach to oestrogen, which can contribute to tumour growth.

Giredestrant – an investigational next-generation SERD and full antagonist – is designed to block oestrogen from binding to the oestrogen receptor, triggering its breakdown (known as degradation) and stopping or slowing down the growth of cancer cells. It is being investigated in five company-sponsored phase III clinical trials that span multiple treatment settings and lines of therapy.