The US Food and Drug Administration (FDA) has granted accelerated approval to AstraZeneca's Etcamah (camizestrant), used with a cyclin-dependent kinase (CDK) 4/6 inhibitor (abemaciclib, palbociclib or ribociclib), for breast cancer.
This combo is approved for adults with hormone receptor (HR)-positive, HER2-negative locally advanced or metastatic breast cancer.
The clearance applies when an estrogen receptor 1 (ESR1) mutation is detected during treatment with an aromatase inhibitor and a CDK4/6 inhibitor, as identified by an FDA-authorised test.
It is based on findings from the SERENA-6 Phase III trial, presented at the 2025 American Society of Clinical Oncology Annual Meeting.
At a planned interim analysis, the Etcamah combination reduced the risk of disease progression or death by 56% compared with an aromatase inhibitor (anastrozole or letrozole) plus a CDK4/6 inhibitor.
Median progression-free survival was 16.0 months versus 9.2 months.
A later pre-planned analysis showed time to second disease progression of 25.7 months versus 19.1 months. Overall survival data remain immature and will continue to be assessed.
Safety findings matched the known profiles of each medicine, with no new concerns and low discontinuation rates in both arms.
SERENA-6 enrolled 315 patients and used circulating tumour deoxyribonucleic acid (ctDNA) blood testing at routine scans every two to three months.
The FDA simultaneously approved a companion diagnostic that detects emerging ESR1 resistance mutations in ctDNA.
AstraZeneca oncology haematology business unit executive vice-president Dave Fredrickson said: “Today's approval is the tenth granted by the FDA this year across AstraZeneca's portfolio and our fourth in breast cancer alone.
“The Etcamah combination reflects AstraZeneca's leadership in redefining breast cancer care by pioneering a new approach using circulating tumour DNA and is the first and only medicine of its type in the first-line setting.”
Etcamah, an oral selective estrogen receptor degrader given once daily at 75mg alongside a CDK4/6 inhibitor, is cleared in more than 30 countries, including Canada, Japan, the UK and the EU.
In July 2026, AstraZeneca and Sino Biopharmaceutical’s subsidiary Chia Tai Tianqing Pharmaceutical Group (CTTQ) signed an exclusive licence agreement for TQC3721.
