FDA approves AstraZeneca's Etcamah for HR-positive breast cancer
The approval covers Etcamah combined with a CDK4/6 inhibitor for first-line advanced HR-positive, HER2-negative breast cancer patients who develop an ESR1 mutation.
AstraZeneca announced on 07 September 2026 that the FDA approved Etcamah (camizestrant) in combination with a cyclin-dependent kinase (CDK) 4/6 inhibitor (abemaciclib, palbociclib or ribociclib) for adult patients with hormone receptor (HR)-positive, HER2-negative, locally advanced or metastatic breast cancer upon detection of ESR1 mutation during aromatase inhibitor (AI) and CDK4/6 inhibitor therapy, based on an FDA-authorised test.1
The company said the accelerated approval drew on results from the SERENA-6 Phase III trial, which were presented at the 2025 ASCO Annual Meeting and published simultaneously in The New England Journal of Medicine.1 Findings from an interim analysis showed the Etcamah combination cut the risk of disease progression or death by 56% compared with standard AI-based therapy (anastrozole or letrozole) plus a CDK4/6 inhibitor, based on a hazard ratio of 0.44 (95% CI: 0.31-0.60; p<0.00001), with median progression-free survival of 16.0 months versus 9.2 months.1
A later analysis found a statistically significant PFS2 benefit of 25.7 months versus 19.1 months (HR: 0.63; 95% CI: 0.46-0.86; p=0.00373), while overall survival data continued to trend in favor of the Etcamah arm (HR: 0.87; 95% CI: 0.57-1.30).1 The trial will keep tracking overall survival as a key secondary endpoint.1
Regarding trial design, the global study included 315 adult patients with confirmed HR-positive, HER2-negative advanced breast cancer who were on AI plus CDK4/6 inhibitor treatment as their first-line therapy.1 The primary endpoint was investigator-assessed progression-free survival, with overall survival and PFS2 as secondary endpoints.1
Alongside the drug approval, the FDA also cleared a companion diagnostic to detect emerging ESR1 resistance mutations via circulating tumor DNA, making SERENA-6 the first global, double-blind, registrational Phase III trial to use this ctDNA-guided approach to time a treatment switch before disease progression.1 Safety data showed the combination's profile was consistent with each medicine's known safety record, with no new safety signals and low, similar discontinuation rates across both arms.1
Written by readthrough’s AI from the linked primary sources and fact-checked against them automatically before publishing. Not investment advice.