A new drug combination has significantly delayed disease progression in the most common form of advanced breast cancer, detailed results published in the New England Journal of Medicine show. The phase 3 evERA trial tested giredestrant plus everolimus against standard endocrine therapy plus everolimus.

In patients with ER-positive, HER2-negative advanced breast cancer whose disease had progressed after CDK4/6 inhibitor treatment, the combination cut the risk of progression or death by 44 per cent. Median progression-free survival was 8.8 months versus 5.5 months.

In patients with ESR1 mutations, the benefit was larger: a 62 per cent risk reduction, with median progression-free survival of 10.0 months versus 5.5 months. Overall survival data are still maturing but trend favourably.

The safety profile was manageable and consistent with the known effects of the two drugs. The US FDA has set decision dates of November 30, 2026, and December 18, 2026, for giredestrant applications in early-stage and advanced disease.