Phase III study of ribociclib (LEE011) plus fulvestrant for the treatment of postmenopausal patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2–) advanced breast cancer (aBC) who have received no or only one line of prior endocrine treatment (ET): MONALEESA-3.

摘要: TPS624Background: Inhibition of the cyclin D–cyclin dependent kinase (CDK)4/6–retinoblastoma pathway may overcome ET resistance and enhance the efficacy of existing ET regimens in HR+, HER2– aBC. Combination of the CDK4/6 inhibitor ribociclib (LEE) with fulvestrant (FUL) has demonstrated potent tumor regressions in preclinical HR+ breast cancer (BC) models (O’Brien et al. Cancer Res 2014;74:Abstr 4756). Methods: In this phase III, double-blind study (NCT02422615), postmenopausal patients with HR+, HER2– aBC (N≈660) will be randomized 2:1 to oral LEE (600 mg QD on Days 1–21 of each 28-day cycle) + FUL (500 mg intramuscularly on Days 1 and 15 of Cycle 1 and Day 1 of each cycle thereafter; Arm A) or placebo + FUL (Arm B). Randomization is stratified by presence of lung or liver metastases and prior ET. Patients may have newly diagnosed aBC that is treatment-naïve, relapsed BC that …