Dr Mayer talks to ecancer at ESMO 2025 about data she presented from the evERA BC phase III trial.

This evaluated giredestrant plus everolimus versus standard-of-care endocrine therapy (SOC ET) plus everolimus in patients with ER-positive, HER2-negative advanced breast cancer who had progressed after CDK4/6 inhibitor therapy. 373 patients were randomised (giredestrant plus everolimus: 183; SOC ET + E: 190). About 55% had ESR1 mutations.

Giredestrant plus everolimus was found to improve investigator-assessed progression-free survival (INV-PFS) in both ESR1-mutant and overall populations, while common adverse events included stomatitis (47%), diarrhoea (27%), and anaemia (24%), with grade 3/4 events being infrequent. Safety was manageable, with few treatment discontinuations.

Dr Mayer notes that giredestrant plus everolimus offers a meaningful progression free survival benefit with a manageable safety profile in patients with ER+, HER2– aBC after CDK4/6 inhibitor therapy, representing a promising new post-CDK4/6i treatment option.