AstraZeneca (AZN.US) major new breast cancer drug approved for marketing in the European Union

The Zhitong Finance App learned that on July 23, AstraZeneca (AZN.US) announced that its combination of Etcamah (camizestrant) and cyclin-dependent kinase (CDK) 4/6 inhibitors (pipebasil, ribosil, or abecilib) has been approved in the EU to treat adult patients with estrogen receptor (ER) positive and HER2 negative locally advanced or metastatic breast cancer, provided that ESR1 mutations are detected and the disease does not progress during treatment with first-line endocrine therapy combined with CDK4/6 inhibitors.

AstraZeneca said etcamah is currently the only next-generation oral SERD approved for first-line breast cancer treatment. Previously, the product was approved for listing in Japan, the United Arab Emirates and Saudi Arabia, and applications for listing have also been submitted in the US and other regions.

This approval is based on the positive results of the critical Phase III SERENA-6 study. This is a randomized, double-blind, global multicenter phase III clinical trial to evaluate the efficacy and safety of etcamah in combination with CDK4/6 inhibitors in the treatment of HR-positive and HER2-negative advanced breast cancer patients.

In a predetermined midterm analysis, compared with standard treatment with AI combined with CDK4/6 inhibitors, Etcamah combination reduced the risk of disease progression or death by 56% (HR 0.44; 95% CI: 0.31-0.60; p<0.00001), and the median progression-free survival (PFS) was 16 months, compared to 9.2 months for the control group. Data updated at the 2026 ASCO conference showed that after switching to Camizestrant, the median change in total ctDNA in week 8 decreased by 99%; while the control group that continued AI+CDK4/6 increased by 64%.

In terms of safety, the safety of the joint protocol is consistent with the known safety of each drug. No new safety issues were identified, and both groups had very low and similar withdrawal rates.

It is worth noting that in April 2026, the US FDA ODAC did not support the launch of Etcamah with a 3:6 vote. They believed that existing clinical data could not be confirmed, and that the early drug exchange plan before imaging advances could bring substantial and clinically valuable long-term benefits to patients. The FDA then extended the PDUFA date to review more supplementary data.