- The MONALEESA-3 randomized controlled trial (RCT) showed that ribociclib plus fulvestrant was tied to an OS advantage over fulvestrant alone in postmenopausal patients with hormone receptor (HR)-positive, HER2-negative advanced breast cancer.
Why this matters
- This is the second interim analysis of OS.
- Previous results of this same trial showed that ribociclib+fulvestrant had a PFS advantage over fulvestrant alone.
- International, placebo-controlled, phase 3 RCT of ribociclib+fulvestrant vs placebo+fulvestrant as first-line or second-line therapy (N=726) in patients with HR+/HER2− advanced breast cancer (metastatic disease or locoregional recurrent disease not amenable to curative treatments).
- Funding: Novartis.
- Median follow-up, 39.4 months.
- Estimated OS at 42 months:
- 57.8% in the ribociclib group (95% CI, 52.0%-63.2%) vs
- 45.9% (95% CI, 36.9%-54.5%) in the placebo group; and
- 28% difference in the relative risk for death: HR, 0.72 (P=.00455).
- Subgroup analysis of first-line and second-line treatments showed similar results.
- A descriptive analysis of median PFS showed an advantage for the ribociclib group receiving first-line therapy (33.6 [95% CI, 27.1-41.3] vs 19.2 [95% CI, 14.9-23.6] months).
- Limited to specific patient population included in the trial.