The incidence of breast cancer (BC) is increasing in most Asian female populations, with a higher proportion of early onset (premenopausal) BC.1,2 Therefore improved hormonal treatments for women with premenopausal BC are needed. The cyclin D–cyclin dependent kinase (CDK) 4/6–INK4–Rb pathway is frequently dysregulated in HR+ BC; adding ribociclib, a highly selective CDK4/6 inhibitor, to standard first-line endocrine therapy (ET) for premenopausal HR + , HER2– aBC (tamoxifen or NSAIs with ovarian function suppression) may provide therapeutic benefit vs ET alone.
Ph III study of continuous daily tamoxifen (20 mg) or NSAI (letrozole 2.5 mg or anastrozole 1 mg) with subcutaneous goserelin implant (3.6 mg Day 1 of each 28-day cycle) and ribociclib (600 mg once daily, Day 1–21 of each 28-day cycle) or matching placebo (MONALEESA-7; NCT02278120). Key inclusion criteria: pre/perimenopausal; HR + , HER2– aBC; ECOG PS ≤ 1. Patients receiving ≤ 1 line of chemotherapy and/or ≤ 14 days of tamoxifen or NSAI (letrozole or anastrozole) with/without goserelin for aBC are eligible; prior treatment with CDK4/6 inhibitors is prohibited. Patients (N ≈ 660) are randomized (1:1) to receive either ribociclib or placebo combined with tamoxifen + goserelin or NSAI + goserelin. Stratification: presence of lung and/or liver metastases; prior chemotherapy for aBC; endocrine combination partner. Primary endpoint: progression-free survival (PFS; local assessment/RECIST 1.1); key secondary endpoint: overall survival. Other secondary endpoints include PFS (blinded independent review/RECIST 1.1), safety, tolerability, response rate, clinical benefit rate, time to response, duration of response, and health-related quality of life (EORTC QLQ-C30). Tumor and blood samples will be collected for biomarker and PK assessments at several timepoints. Global recruitment is ongoing including in Australia, Hong Kong, India, Korea, Singapore, Taiwan, and Thailand.
1. Lum et al Carcinogenesis 2008;29:754.
2. Shin et al Cancer Sci 2010;101:1241.
Clinical trial identification
S.-A. Im: grants from Research Funding from AstraZeneca, outside the submitted work. D. Tripathy: grants from Novartis, personal fees from Novartis, during the conduct of the study. A. Bardia: personal fees from Novartis, personal fees from Genentech, personal fees from Immunomedics, during the conduct of the study.
S. Hurvitz: grants and other from Genentech/Roche, Novartis, Boehringer Ingelheim and Pfizer, grants from GlaxoSmithKline, Sanofi, Amgen, OBI Pharma, outside the submitted work. N. Harbeck other from Novartis, during the conduct of the study; personal fees from Novartis, personal fees from Pfizer, outside the submitted work. C. Germa: personal fees from Novartis, outside the submitted work. G. Hughes: personal fees from Novartis Pharma AG, outside the submitted work. L. McLean: personal fees and other from Novartis Pharmaceuticals during the conduct of the study and outside the submitted work. M. Horan: personal fees from Novartis, during the conduct of the study. All other authors have declared no conflicts of interest.