Clinical Trial Analysis

MONALEESA-2

Phase 3 First-Line Advanced BC

Ribociclib combination achieves unprecedented Median Overall Survival >5 Years.

Absolute OS Gain

12.5 Months

Longest reported survival benefit in this setting.
63.9 mo (Ribociclib) vs 51.4 mo (Placebo).

Study Architecture

Population Postmenopausal, HR+/HER2- Advanced BC (N=668).
Follow-up Median 80 months (6.6 years).
Investigational: Ribociclib (600mg) + Letrozole
Control: Placebo + Letrozole

Overall Survival Benefit

HR 0.76 (95% CI 0.63-0.93; P=0.008) — 24% risk reduction.

Key Efficacy Milestones

Chemotherapy delayed by nearly 1 year (HR 0.74).

Relative Risk Reduction
24%
Reduction in mortality risk vs placebo.
6-Year Survival Rate
44.2%
Alive at 72 months (vs 32.0%).
Recommendation

Adopt Ribociclib + Letrozole as standard-of-care.

Clinically meaningful benefit; no new safety signals.

ArmPlacebo
Months51.4