NEW YORK (Reuters Health) - First-line therapy with the combination of ribociclib and letrozole increased overall survival by 24% over letrozole alone among patients with hormone receptor (HR)-positive, HER2-negative advanced breast cancer, according to final results from the MONALEESA-2 phase-3 study.
Median overall survival was 63.9 months with the combination compared with 51.4 months when letrozole was given with placebo (P=0.008), researchers report in the New England Journal of Medicine.
After a median follow-up of 6.6 years, 54.2% of ribociclib recipients had died versus 65.6% of placebo patients.
Novartis, which paid for the study of 668 women and markets the CDK4/6 inhibitor under the brand name Kisqali, originally released the survival data in September.
"The Kaplan-Meier analysis shows that the overall survival benefit of ribociclib began to emerge at approximately 20 months and continued to increase with longer follow-up, as indicated by survival at 5 years and 6 years. The overall survival benefit of ribociclib was generally consistent across patient subgroups," Dr. Gabriel Hortobagyi of the University of Texas MD Anderson Cancer Center, in Houston, and colleagues report.
The most common grade-3 or grade-4 adverse event was neutropenia, which occurred in 63.8% of ribociclib recipients versus 1.2% who received placebo.
Dr. Hortobagyi's group had previously reported that ribociclib significantly extends progression-free survival in this trial.
Other MONALEESA trials have also demonstrated the effectiveness of the drug.
Ribociclib, at the dose given in the study, costs about $5,000 a month, according to prices on goodrx.com.
SOURCE: https://bit.ly/3sK2w1V The New England Journal of Medicine, online March 10, 2022.
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