MONALEESA-2: First-Line Ribociclib + Letrozole Extends Median OS to >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. DOI: 10.1056/NEJMoa2114663. (MONALEESA-2; NCT01958021)

In postmenopausal patients with HR+/HER2- advanced breast cancer, combination therapy demonstrates unprecedented survival benefits.

Population

N = 668
Postmenopausal women
Dx: HR+/HER2- Advanced BC
Setting: First-line

Protocol

Design: Phase 3, Rand., Dbl-blind
Exp: Ribociclib (600mg) + Letrozole
Ctrl: Placebo + Letrozole

Follow-Up

Median Duration: 80 Months
(6.6 Years)
Longest for this setting

Median Overall Survival (mOS)

63.9 Months

Absolute survival gain of 12.5 months vs. Placebo.

Median Overall Survival Comparison

Survival & Risk

24%

Relative Risk Reduction HR 0.76 (95% CI, 0.63-0.93; P=0.008)

6-Year Landmark Survival Rate

Delay in Chemotherapy

Ribociclib significantly delayed the median time to first subsequent chemotherapy compared to placebo.

11.7 Months additional delay

Recommendation: Preferred Standard-of-Care

Given the unprecedented median overall survival exceeding 5 years and consistent benefit across subgroups, Ribociclib + Letrozole should be considered a preferred regimen for first-line treatment of postmenopausal patients with HR+/HER2- advanced breast cancer.

AbbreviationsQuick

Abbreviations: 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

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