Positive high-level results from the CAPItello-291 Phase III trial showed that AstraZeneca plc (LON:AZN) capivasertib in combination with Faslodex (fulvestrant) demonstrated a statistically significant and clinically meaningful improvement in progression-free survival (PFS) versus placebo plus Faslodex in patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-low or negative locally advanced or metastatic breast cancer, following recurrence or progression on or after endocrine therapy (with or without a CDK4/6 inhibitor).
The trial met both primary endpoints, improving PFS in the overall patient population and in a prespecified biomarker subgroup of patients whose tumours had qualifying alterations in the PIK3CA, AKT1 or PTEN genes. Although the overall survival (OS) data were immature at the time of the analysis, early data are encouraging. The trial will continue to assess OS as a key secondary endpoint.
The safety profile of capivasertib plus Faslodex was similar to that observed in previous trials evaluating this combination.
Breast cancer is the most common cancer worldwide, with an estimated 2.3 million patients diagnosed in 2020.1 Approximately 70% of breast cancer tumours are considered HR-positive and HER2-low or negative.2 Endocrine therapies are widely used for the treatment of HR-positive breast cancer, but many patients with advanced disease develop resistance to 1st-line CDK4/6 inhibitors and estrogen receptor-targeting therapies, underscoring the need for additional options.3
Nicholas Turner, MD, PhD, Professor of Molecular Oncology at The Institute of Cancer Research, London, and The Royal Marsden NHS Foundation Trust, London, UK, and principal investigator in the CAPItello-291 Phase III trial, said: “The CAPItello-291 Phase III trial results show capivasertib offers a clinically meaningful improvement in progression free survival for patients with HR-positive breast cancer. This potential new medicine could give people more time with their cancer under control, which is a priority for patients and their families.”
Susan Galbraith, Executive Vice President, Oncology R&D, AstraZeneca, said: “These exciting data in an all-comers population indicate that capivasertib could become a new first-in-class treatment option for patients with HR-positive breast cancer. These patients often experience tumour progression on, or resistance to, available endocrine therapies for advanced disease and urgently need new therapies that extend the effectiveness of endocrine-based treatment approaches.”
The data will be presented at a forthcoming medical meeting and shared with global health authorities.
AstraZeneca has a comprehensive portfolio of approved and potential new medicines in development for patients with breast cancer. In addition to these results, the Company is also announcing today results from the SERENA-2 Phase II trial of camizestrant, the next-generation oral selective estrogen receptor degrader (ngSERD) in advanced estrogen receptor (ER)-positive breast cancer.
