Announcement • Jul 24
AstraZeneca's Etcamah Approval in the Eu for ER+ Breast Cancer
AstraZeneca's Etcamah (camizestrant) in combination with a cyclin-dependent kinase (CDK) 4/6 inhibitor (palbociclib, ribociclib or abemaciclib) has been approved in the European Union (EU) for the treatment of adult patients with estrogen receptor (ER)-positive, HER2-negative locally advanced or metastatic breast cancer upon detection of ESR1 mutation and without disease progression during 1st-line endocrine therapy in combination with a CDK4/6 inhibitor. In a planned interim analysis, the Etcamah combination reduced the risk of disease progression or death by 56% versus standard-of-care treatment with an aromatase inhibitor (AI) (anastrozole or letrozole) in combination with a CDK4/6 inhibitor (based on a hazard ratio [HR] of 0.44; 95% confidence interval [CI]:0.31-0.60; p<0.00001; median progression-free survival (PFS) 16.0 versus 9.2 months). In Europe, breast cancer remains the leading cause of cancer death among women, with more than 140,000 deaths in 2024 and more than 540,000 patients diagnosed in the same year.2 Hormone receptor (HR)-positive breast cancer, characterised by the expression of estrogen or progesterone receptors, or both, is the most common subtype of breast cancer with 70% of tumours considered HR-positive and HER2-negative.3 More than 97% of HR-positive breast cancer tumours are ER-positive.4,5 Across the UK, France, Germany, Spain and Italy, approximately 37,000 patients with HR-positive metastatic breast cancer are treated with a medicine in the 1st-line setting; most frequently with endocrine therapies paired with CDK4/6 inhibitors.6-8 However, many patients have tumours that develop resistance to these therapies, at which point treatment options are limited and survival rates are low, with only approximately 36% of patients anticipated to live beyond five years after diagnosis.3,8 Mutations in the ESR1 gene are a key driver of endocrine resistance and are associated with poor outcomes, emerging during treatment of the disease and becoming more prevalent as the disease progresses.9,10 Approximately 30% of patients with endocrine sensitive HR-positive disease develop ESR1 mutations during 1st-line treatment before disease progression. Data for the key secondary endpoints of time to second disease progression (PFS2) and overall survival (OS) were immature at the time of the interim analysis of the SERENA-6 trial, however, 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) and OS continued to mature in favour of the Etcamah combination (HR: 0.87; 95% CI: 0.57-1.30). The trial will continue to assess OS as a key secondary endpoint. The safety profile of Etcamah in combination with palbociclib, ribociclib or abemaciclib in the SERENA-6 trial was consistent with the known safety profile of each medicine. No new safety concerns were identified, and discontinuations were very low and similar in both arms.1 SERENA-6 is the first global, double-blind, registrational Phase III trial to use a circulating tumour DNA (ctDNA)-guided approach to detect the emergence of endocrine resistance and inform a switch in therapy before disease progression. The innovative trial design used ctDNA monitoring via a blood test at the time of routine tumour scans every two to three months to identify patients for early signs of endocrine resistance via the emergence of ESR1 mutations. Following detection of an ESR1 mutation without disease progression, the endocrine therapy of patients was switched to Etcamah from ongoing treatment with an AI, while continuing combination with the same CDK4/6 inhibitor. Etcamah is also approved in Japan, the United Arab Emirates and Saudi Arabia based on the SERENA-6 Phase III trial. Regulatory applications for Etcamah in this setting are currently under review in several other countries including the US where the US Food and Drug Administration recently extended the Prescription Drug User Fee Act date to review the updated results from the trial.SERENA-6: SERENA-6 is a Phase III, double-blind, randomised trial evaluating the efficacy and safety of Etcamah in combination with a CDK4/6 inhibitor (palbociclib, ribociclib or abemaciclib) versus treatment with an AI (anastrozole or letrozole) in combination with a CDK4/6 inhibitor (palbociclib, ribociclib or abemaciclib) in patients with HR-positive, HER2-negative advanced breast cancer (patients with either locally advanced disease, or metastatic disease) whose tumours have an emergent ESR1 mutation. The global 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. The primary endpoint of the SERENA-6 trial is PFS as assessed by investigator, with secondary endpoints including OS, and PFS2 by investigator assessment. Etcamah: Etcamah (camizestrant) is a potent, next-generation oral selective estrogen receptor degrader (SERD) and complete ER antagonist, administered orally, once daily. The recommended dose of Etcamah in combination with a CDK4/6 inhibitor is 75mg. Etcamah in combination with a CDK4/6 inhibitor (palbociclib, ribociclib or abemaciclib) is approved in the EU, Japan and several other countries for the treatment of adult patients with HR-positive (or ER-positive), HER2-negative locally advanced or metastatic breast cancer upon detection or emergence of ESR1 mutation and without disease progression during 1st-line endocrine therapy based on the results from the SERENA-6 trial. The broad, robust and innovative Etcamah clinical development programme, including the SERENA-4, CAMBRIA-1 and CAMBRIA-2 Phase III trials, is evaluating the safety and efficacy of Etcamah when used as a monotherapy or in combination with CDK4/6 inhibitors to address a number of areas of unmet need in HR-positive, HER2-negative breast cancer. Etcamah has demonstrated anti-cancer activity across a range of preclinical models, including those with ER-activating mutations. In the SERENA-2 Phase II trial, camizestrant demonstrated a statistically significant and clinically meaningful improvement in PFS versus Faslodex (fulvestrant) in the overall trial population, including in patients with ESR1 tumour mutations irrespective of prior treatment with CDK4/6 inhibitors in patients with ER-positive locally advanced or metastatic breast cancer, previously treated with endocrine therapy. The SERENA-1 Phase I trial demonstrated that camizestrant is well tolerated and has a promising anti-tumour profile when administered alone or in combination with palbociclib, ribociclib and abemaciclib; three widely used CDK4/6 inhibitors.