US FDA Approves AstraZeneca's Etcamah with CDK4/6 Inhibitor for HR-Positive Advanced Breast Cancer

Key facts

• Etcamah (camizestrant) in combination with a CDK4/6 inhibitor (abemaciclib, palbociclib or ribociclib) has been approved in the US for adult patients with HR-positive, HER2-negative, locally advanced or metastatic breast cancer upon detection of ESR1 mutation during aromatase inhibitor and CDK4/6 inhibitor therapy.
• The approval was based on the SERENA-6 Phase III trial, in which Etcamah in combination with a CDK4/6 inhibitor reduced the risk of disease progression or death by 56% versus standard-of-care treatment with an AI in combination with a CDK4/6 inhibitor (HR 0.44; 95% CI 0.31-0.60; p<0.00001; median PFS 16.0 versus 9.2 months).
• A subsequent pre-planned analysis demonstrated a statistically significant and clinically meaningful PFS2 benefit of 25.7 months versus 19.1 months in favour of the Etcamah combination (HR 0.63; 95% CI 0.46-0.86; p=0.00373).
• Concurrently with this approval, the FDA also approved a companion diagnostic test to detect emerging ESR1 resistance mutations in the circulating tumour DNA (ctDNA) of patients with HR-positive, HER2-negative advanced or metastatic breast cancer.
• SERENA-6 is the first global, double-blind, registrational Phase III trial to use a ctDNA-guided approach to detect the emergence of endocrine resistance and inform a switch in therapy before disease progression.
• Etcamah is also approved in more than 30 countries across the globe, including in the EU, Japan, Canada, the UK and several other countries based on the SERENA-6 Phase III trial.
• Etcamah is a potent, next-generation oral selective estrogen receptor degrader (SERD) and complete ER antagonist, administered orally once daily, with a recommended dose of 75mg in combination with a CDK4/6 inhibitor.
• The global SERENA-6 trial enrolled 315 adult patients with histologically confirmed HR-positive, HER2-negative advanced breast cancer undergoing treatment with an AI in combination with a CDK4/6 inhibitor as 1st-line treatment.
• Approximately 30% of patients with endocrine sensitive HR-positive disease develop ESR1 mutations during 1st-line treatment before disease progression.
• More than two million patients were diagnosed with breast cancer in 2024, with more than 690,000 deaths globally.