Theme

MONALEESA-2 Final Analysis

First-Line Ribociclib + Letrozole Achieves "Insurmountable" Median Overall Survival of Over 5 Years

Source
Source: Hortobagyi GN, Stemmer SM, Burris HA, et al. Overall Survival with Ribociclib plus Letrozole in Advanced Breast Cancer. N Engl J Med. 2022;386:942-50. MONALEESA-2 ClinicalTrials.gov number, NCT01958021.
Population (N=668)

Postmenopausal
HR+/HER2- Advanced Breast Cancer
First-line systemic therapy

Investigational Arm (n=334)

Ribociclib + Letrozole

600 mg/day (3-on/1-off) + 2.5mg
Control Arm (n=334)

Placebo + Letrozole

Continuous daily dosing
LONGEST REPORTED MEDIAN OVERALL SURVIVAL
63.9 Months

Median OS for Ribociclib Arm vs. 51.4 Months for Placebo

Overall Survival (Months)
5-Year Survival Rate (60 mo)
Relative Risk Reduction
24%
HR 0.76 (95% CI, 0.63-0.93; P=0.008)
Absolute Survival Benefit
+12.5 Mo
Extension vs. endocrine therapy alone

Recommendation: Standard of Care

Integrate Ribociclib plus Letrozole as the first-line treatment for postmenopausal patients with HR+/HER2- advanced breast cancer. The data confirms a clinically meaningful overall survival benefit exceeding one year compared to endocrine therapy alone.

AbbreviationsQuick
CDK4/6, cyclin-dependent kinases 4 and 6; CI, confidence interval; ECOG, Eastern Cooperative Oncology Group; ER, estrogen receptor; HER2, human epidermal growth factor receptor 2; HR, hormone receptor; NE, could not be estimated; PgR, progesterone receptor.
Bibliography8
  1. Hortobagyi GN, Stemmer SM, Burris HA, et al. Overall Survival with Ribociclib plus Letrozole in Advanced Breast Cancer. N Engl J Med. 2022;386:942-50. (DOI: 10.1056/NEJMoa2114663)
  2. Hortobagyi GN, Stemmer SM, Burris HA, et al. Ribociclib as first-line therapy for HR-positive, advanced breast cancer. N Engl J Med 2016;375:1738-48.
  3. Im S-A, Lu Y-S, Bardia A, et al. Overall survival with ribociclib plus endocrine therapy in breast cancer. N Engl J Med 2019; 381: 307-16.
  4. Slamon DJ, Neven P, Chia S, et al. Overall survival with ribociclib plus fulvestrant in advanced breast cancer. N Engl J Med 2020; 382: 514-24.
  5. Cristofanilli M, Turner NC, Bondarenko I, et al. Fulvestrant plus palbociclib versus fulvestrant plus placebo for treatment of hormone-receptor-positive, HER2-negative metastatic breast cancer that progressed on previous endocrine therapy (PALOMA-3). Lancet Oncol 2016; 17:425-39.
  6. Goetz MP, Toi M, Campone M, et al. MONARCH 3: abemaciclib as initial therapy for advanced breast cancer. J Clin Oncol 2017;35:3638-46.
  7. Cardoso F, Paluch-Shimon S, Senkus E, et al. 5th ESO-ESMO international consensus guidelines for advanced breast cancer (ABC 5). Ann Oncol 2020;31:1623-49.
  8. National Comprehensive Cancer Network. Metastatic breast cancer. 2020. (link)