Phase III Randomized Study of Ribociclib and Fulvestrant in Hormone Receptor–Positive, Human Epidermal Growth Factor Receptor 2–Negative Advanced Breast Cancer: MONALEESA-3
Slamon DJ, Neven P, Chia S, et al J Clin Oncol. 2018;36:2465-2472
Study Summary
The MONALEESA-3 phase 3 study evaluated ribociclib plus fulvestrant in patients with hormone receptor–positive (HR+) and HER2-negative (HER2-) advanced breast cancer who were treatment-naıve or had received up to one line of prior endocrine therapy in the advanced setting.
This international study randomly assigned 484 postmenopausal women to ribociclib plus fulvestrant, and 242 to placebo plus fulvestrant. Median progression-free survival (PFS), the study’s primary endpoint, was significantly improved with ribociclib plus fulvestrant versus placebo plus fulvestrant: 20.5 months versus 12.8 months.
Treatment effects were observed in patients who were treatment-naive in the advanced setting as well as in patients who had received up to one line of prior endocrine therapy for advanced disease. Among patients with measurable disease, the overall response rate was 41% for ribociclib plus fulvestrant and 29% for placebo plus fulvestrant.
Grade 3 adverse events reported by at least 10% of patients in either arm included neutropenia (46.6% ribociclib vs 0% placebo) and leukopenia (13.5% ribociclib vs 0% placebo); the only grade 4 event reported by at least 5% of patients was neutropenia (6.8% ribociclib vs 0% placebo).
