AstraZeneca announces results from SERENA-6 Phase III trial

Positive results from the SERENA-6 Phase III trial showed that AstraZeneca’s (AZN) camizestrant in combination with a cyclin-dependent kinase 4/6 inhibitor demonstrated a highly statistically significant and clinically meaningful improvement in progression-free survival, PFS. The trial evaluated switching to the camizestrant combination versus continuing standard-of-care treatment with an aromatase inhibitor in combination with a CDK4/6 inhibitor in the 1st-line treatment of patients with hormone receptor-positive, HER2-negative advanced breast cancer whose tumors have an emergent ESR1 mutation. These results will be presented today during the Plenary Session at the 2025 American Society of Clinical Oncology, ASCO, Annual Meeting in Chicago, IL and simultaneously published in The New England Journal of Medicine. Results showed the camizestrant combination reduced the risk of disease progression or death by 56% compared to standard-of-care treatment as assessed by investigator. Median PFS was 16.0 months for patients who switched to the camizestrant combination versus 9.2 months for the comparator arm. Importantly, a consistent PFS benefit was observed across all CDK4/6 inhibitors and clinically relevant subgroups in the trial, including analysis by age, race, region, time of ESR1 mutation detection and type of ESR1 mutation.