Capivasertib-fulvestrant therapy increases PFS in HR-positive breast cancer

For patients with hormone receptor-positive advanced breast cancer with disease progression during or after treatment with an aromatase inhibitor, capivasertib-fulvestrant therapy results in significantly longer progression-free survival than fulvestrant alone, according to a study published in the June 1 issue of the New England Journal of Medicine.

Nicholas C. Turner, M.D., Ph.D., from the Royal Marsden Hospital in London, and colleagues conducted a randomized trial involving premenopausal, perimenopausal, and postmenopausal women and men with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer who had a relapse or disease progression during or after aromatase inhibitor treatment, with or without previous cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor therapy. A total of 708 participants were randomly assigned to receive capivasertib plus fulvestrant or placebo plus fulvestrant in a 1:1 ratio.

The researchers found that the median progression-free survival was 7.2 and 3.6 months in the capivasertib-fulvestrant group and the placebo-fulvestrant group, respectively, in the overall population (hazard ratio for progression or death, 0.60). The median progression-free survival was 7.3 and 3.1 months, respectively, in the AKT pathway-altered population (hazard ratio, 0.50). Rash and diarrhea were the most frequent adverse events of grade 3 or higher in patients receiving capivasertib-fulvestrant.

"Our findings suggest that capivasertib-fulvestrant treatment improved outcomes regardless of previous exposure to a CDK4/6 inhibitor and reinforce the evidence that single-agent endocrine therapy has poor outcomes after receipt of a CDK4/6 inhibitor," the authors write.

The study was funded by AstraZeneca, the manufacturer of capivasertib. In addition, several authors disclosed ties to industry.