Can KISQALI + fulvestrant help postmenopausal patients with metastatic breast cancer live longer?
KISQALI® (ribociclib), in combination with fulvestrant, demonstrated a statistically significant overall survival (OS) improvement in first- and second-line (1L and 2L) postmenopausal patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) metastatic breast cancer (mBC) in the phase III MONALEESA-3 trial (median follow-up of 39 months; HR=0.724 [95% CI: 0.568-0.924]; P=0.00455). Review OS data from the MONALEESA-3 trial below.1-3
MONALEESA-3: KISQALI + fulvestrant in postmenopausal patients, data from the 1L subgroup
OVERALL SURVIVAL
Median overall survival exceeded 5.5 years with KISQALI + fulvestrant in 1L postmenopausal patients
At a median follow-up of 71 months (exploratory analysis)
Hazard ratio is based on unstratified Cox model.5
Results from the 71-month analysis and the 39-month subgroup analysis were not prespecified and were observational in nature; as such, there was no prespecified statistical procedure controlling for type 1 error.
Exploratory subgroup analysis of a 1L subgroup of patients receiving KISQALI + fulvestrant (n=237) or placebo + fulvestrant (n=128): At a median follow-up of 39 months, mOS was not reached with KISQALI + fulvestrant vs 45.1 months with placebo + fulvestrant; HR=0.70 (95% CI: 0.48-1.02)3
Statistically significant improvement in overall survival in the 1L/2L ITT population1,3:
In the prespecified OS analysis at a median follow-up of 39 months, mOS was not reached with KISQALI + fulvestrant (95% CI: 42.5-NR) vs 40 months with placebo + fulvestrant (95% CI: 37.0-NR); HR=0.724 (95% CI: 0.568-0.924); P=0.00455
1L, first line; 2L, second line; HR, hazard ratio; ITT, intent to treat; mOS, median overall survival; NR, not reached.
MONALEESA-3: KISQALI + fulvestrant in 1L/2L postmenopausal patients
TIME TO CHEMOTHERAPY
Median time to chemotherapy delayed 4 years in 1L/2L postmenopausal patients
At a median follow-up of 56 months (exploratory analysis)
Time to chemotherapy was evaluated in a post hoc exploratory analysis and was defined as the time from randomization to the beginning of the first chemotherapy after discontinuing study treatment. There was no prespecified statistical procedure controlling for type 1 error3
MONALEESA-3 was a randomized, double-blind, placebo-controlled, phase III study of KISQALI + fulvestrant (n=484) vs placebo + fulvestrant (n=242) in postmenopausal patients with HR+/HER2- mBC who received no or only 1 line of prior ET for advanced disease. OS was a secondary end point; PFS was the primary end point.1,2
ET, endocrine therapy; HER2-, human epidermal growth factor receptor 2-negative; HR+, hormone receptor-positive; mBC, metastatic breast cancer; mTTC, median time to chemotherapy; OS, overall survival; PFS, progression-free survival.