Posted: Wednesday, January 25, 2023
Nicholas Turner, MD, PhD, of The Royal Marsden Hospital, London, and colleagues conducted the phase III CAPItello-291 trial to determine whether patients with advanced aromatase inhibitor–resistant, hormone receptor–positive, HER2-negative breast cancer may benefit from treatment with the pan-AKT inhibitor capivasertib in combination with fulvestrant. Their findings were presented during the 2022 San Antonio Breast Cancer Symposium (SABCS; Abstract GS3-04).
“The improvement in progression-free survival with relatively well-tolerated side effects is extremely encouraging,” commented Dr. Turner in a press release from the American Association for Cancer Research. “We are hopeful that capivasertib will become a new treatment option for patients whose cancer has progressed on a regimen containing an endocrine therapy.”
Eligible patients were randomly assigned to receive fulvestrant in combination with either capivasertib (n = 355) or a placebo (n = 353). Of the study population, 41% harbored an AKT pathway mutation.
A total of 551 and 236 progression-free survival events had occurred in the overall and pathway-altered populations, respectively, at primary analysis. In the overall population, the median duration of progression-free survival was prolonged with capivasertib compared with the placebo (7.2 vs. 3.6 months; hazard ratio [HR] = 0.60). The median duration of progression-free survival in the AKT pathway–altered population was 7.3 months with capivasertib and 3.1 months with the placebo (HR = 0.50). The objective response rates in the overall and AKT pathway–altered populations were 22.9% and 28.8% with capivasertib and 12.2% and 9.7% with the placebo, respectively.
Diarrhea, rash, and nausea were the most frequently reported all-grade adverse events with capivasertib. The most common adverse events of grade 3 or higher were rash, diarrhea, and hyperglycemia. Adverse events leading to treatment discontinuation occurred in 13.0% and 2.3% of the capivasertib and placebo arms, respectively.
Disclosure: For full disclosures of the study authors, visit sabcs.org.