AstraZeneca PLC reported that its SERENA-4 Phase III clinical trial failed to meet its primary endpoint of progression-free survival (PFS), dealing a setback to the company's oncology pipeline.
The trial evaluated etcamah (camizestrant) combined with palbociclib, a cyclin-dependent kinase 4/6 inhibitor, versus anastrozole—a aromatase inhibitor—plus palbociclib, in adult patients with estrogen receptor-positive, HER2-negative advanced breast cancer receiving first-line treatment. A numerical improvement in PFS was observed, but it did not reach statistical significance.
The global trial enrolled 1,371 adult patients who had been newly diagnosed with Stage IV de novo or recurrent disease and had not previously received systemic treatment for metastatic disease. The safety profile of the etcamah and palbociclib combination was consistent with the known safety profiles of each individual medicine, with no new safety concerns identified.
Susan Galbraith, executive vice president of oncology haematology research and development at AstraZeneca, said the company is disappointed by the SERENA-4 outcome but intends to sharpen its focus on maximizing the number of patients who can benefit from etcamah based on results from the SERENA-6 trial.
Etcamah combined with a CDK4/6 inhibitor already holds approval in the US, EU, Japan and several other markets for adult patients with hormone receptor-positive, HER2-negative locally advanced or metastatic breast cancer upon detection or emergence of an ESR1 mutation during first-line endocrine-based therapy, based on data from the SERENA-6 Phase III trial.
The company continues to evaluate etcamah in two additional Phase III trials, CAMBRIA-1 and CAMBRIA-2, which together encompass approximately 10,000 patients in early breast cancer settings.












