# Overall Survival with Ribociclib plus Letrozole in Advanced Breast Cancer

Source: https://onco.cc/key-papers/paper-monaleesa-2-n-engl-j-med-2022-update/  
OnCo record `paper-monaleesa-2-n-engl-j-med-2022-update` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Later report from the MONALEESA-2 trial registered as NCT01958021, in New England Journal of Medicine (2022); its title describes an updated or longer-term analysis.

## Summary

Background: In a previous analysis of this phase 3 trial, first-line ribociclib plus letrozole resulted in significantly longer progression-free survival than letrozole alone among postmenopausal patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer. Whether overall survival would also be longer with ribociclib was not known.

Methods: Here we report the results of the protocol-specified final analysis of overall survival, a key secondary end point. Patients were randomly assigned in a 1:1 ratio to receive either ribociclib or placebo in combination with letrozole. Overall survival was assessed with the use of a stratified log-rank test and summarized with the use of Kaplan-Meier methods after 400 deaths had occurred. A hierarchical testing strategy was used for the analysis of progression-free survival and overall survival to ensure the validity of the findings.

Results: After a median follow-up of 6.6 years, 181 deaths had occurred among 334 patients (54.2%) in the ribociclib group and 219 among 334 (65.6%) in the placebo group. Ribociclib plus letrozole showed a significant overall survival benefit as compared with placebo plus letrozole. Median overall survival was 63.9 months (95% confidence interval [CI], 52.4 to 71.0) with ribociclib plus letrozole and 51.4 months (95% CI, 47.2 to 59.7) with placebo plus letrozole (hazard ratio for death, 0.76; 95% CI, 0.63 to 0.93; two-sided P = 0.008). No new safety signals were observed.

Conclusions: First-line therapy with ribociclib plus letrozole showed a significant overall survival benefit as compared with placebo plus letrozole in patients with HR-positive, HER2-negative advanced breast cancer. Median overall survival was more than 12 months longer with ribociclib than with placebo. (Funded by Novartis; MONALEESA-2 ClinicalTrials.gov number, NCT01958021.).

Indexed on Europe PMC as PubMed record 35263519 (DOI 10.1056/nejmoa2114663). Its abstract cites the registry id NCT01958021, which is how it was matched to this trial; no figure has been checked by an editor.

## Fields

- Kind: Key paper
- Last checked: 2026-09-22
- Tags: europepmc-ingest
- Journal: New England Journal of Medicine
- Year: 2022
- DOI: 10.1056/nejmoa2114663
- Authors: Hortobagyi GN, Stemmer SM, Burris HA, et al.
- What it means: A second publication from the MONALEESA-2 trial, later than the first and described in its title as an update or longer-term analysis. Read it with the primary publication linked from the trial page; the record was linked automatically and its figures have not been checked by hand.
- Caveats: Matched to the trial by the registry id cited in the Europe PMC record; the summary reproduces the record's abstract and no figure has been verified against the full paper.; Chosen as a later report by words in its title (updated, long-term, final, overall survival or a year count), not by reading the paper.

## Sources

- N Engl J Med 2022: https://doi.org/10.1056/nejmoa2114663
- PubMed: https://pubmed.ncbi.nlm.nih.gov/35263519/
- Europe PMC: https://europepmc.org/article/MED/35263519
- ClinicalTrials.gov NCT01958021: https://clinicaltrials.gov/study/NCT01958021

## Connected records

- trials: [MONALEESA-2](https://onco.cc/trials/monaleesa-2/)
- journals: [New England Journal of Medicine](https://onco.cc/journals/nejm/)

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