Key clinical point: In patients with hormone receptor (HR)-positive, human epidermal growth receptor (HER)-negative advanced breast cancer, the addition of ribociclib to fulvestrant extends median overall survival by 12 months.
Major finding: The median overall survival was 53.7 months with ribociclib and 41.5 months with placebo (hazard ratio, 0.73; 95% confidence interval, 0.59-0.90 months) at a median follow-up of 56.3 months. Neutropenia was the most common grade 3-4 adverse event.
Study details: A phase 3, randomized, double-blind, placebo-controlled MONALEESA-3 trial including 726 chemotherapy-naïve patients (men and postmenopausal women) with HR-positive, HER2-negative advanced breast cancer randomly assigned 2:1 to receive fulvestrant with either ribociclib or placebo.
Disclosures: The study was funded by the Novartis Pharmaceuticals Corporation. The authors reported advisory/consulting fees, stock ownership, research funding, grants, personal fees, honoraria, travel expenses, and nonfinancial support from various sources outside this work.
Source: Slamon DJ et al. Ann Oncol. 2021 Jun 5. doi: 10.1016/j.annonc.2021.05.353.