- Ribociclib+endocrine therapy (ET) prolonged OS by 29% compared with ET+placebo in patients with hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer (ABC).
- A previous report found that the ribociclib group had 45% longer PFS than the placebo group.
Why this matters
- Ribociclib+ET may be a new first-line treatment for HR+/HER2− ABC.
- Protocol-specified interim analysis of phase 3 MONALEESA-7 double-blind randomized trial of 672 premenopausal or perimenopausal patients with HR+/HER2− ABC in 30 countries who were randomly assigned to ribociclib (600 mg/day administered orally once daily for 21 consecutive days, followed by 7 days off) or placebo.
- All patients received ET (goserelin+nonsteroidal aromatase inhibitor or tamoxifen).
- Funding: Novartis.
- 24.8% died in the ribociclib group; 32.3% in the placebo group.
- At 42 months, the estimated OS was 70.2% in the ribociclib group and 46.0% in the placebo group (HR, 0.71; P=.00973 by log-rank test).
- Similar results were found for the subgroup receiving aromatase inhibitor (HR, 0.70; 95% CI, 0.50-0.98).
- The ribociclib group also had longer time from randomization to disease progression or death during receipt of second-line therapy (HR, 0.69; 95% CI, 0.55-0.87).
- None identified by authors.