Related Experiment Video
Updated: Jun 15, 2025

Using Mouse Mammary Tumor Cells to Teach Core Biology Concepts: A Simple Lab Module
Published on: June 18, 2015
Indirect Treatment Comparison between Ribociclib Combined with Non-Steroidal Aromatase Inhibitors and Ovarian
Diana Lüftner1,2, Maggie Banys-Paluchowski3, Andreas D Hartkopf4
1Immanuel Hospital Märkische Schweiz, Buckow, Germany.
Background:
This study provides an indirect treatment comparison of ribociclib combined with non-steroidal aromatase inhibitors and ovarian function suppression (ribociclib + NSAI + OFS) vs. a frequently used treatment option in German clinical routine (tamoxifen ± OFS) in premenopausal patients with HR-positive (HR+), HER2-negative (HER2-) early breast cancer (BC).
Material And Methods:
Data on premenopausal women treated with ribociclib and tamoxifen were derived from the NATALEE clinical trial (NCT03701334) and the retrospective German data collection CLEAR-B, respectively. NATALEE trial eligibility criteria were applied to the CLEAR-B dataset. Standardized mortality ratio weights were used for propensity score (PS) adjustment to balance study populations. All hazard ratios (HR) were calculated based on a 4-year-observation period for both treatment arms. Effectiveness endpoints comprised invasive and distant disease-free survival (iDFS, dDFS), recurrence-free survival (RFS), and overall survival (OS). Safety-related endpoints were treatment termination (TT) and toxicity-related TT (TTtox). For safety comparisons, the ribociclib arm was divided into groups that discontinued ribociclib + NSAI + OFS or ribociclib only.
Results:
Significant beneficial effects favoring ribociclib + NSAI + OFS (n = 1115) over tamoxifen ± OFS (n = 822) were observed for all effectiveness outcomes (iDFS [HR = 0.5 (95% CI 0.35; 0.71); p < 0.01]; dDFS [HR = 0.52 (95% CI 0.35; 0.77); p = 0.01], RFS [HR = 0.42 (95% CI 0.29; 0.62); p < 0.01], OS [HR = 0.34 (95% CI 0.18; 0.63); p = 0.01]) during the 4-year-observation period. The effect of early treatment discontinuation showed no significant differences between ribociclib + NSAI + OFS and tamoxifen ± OFS (TT-a: HR = 1.2 [95% CI: 0.71; 2.01], p = 0.48; TTtox-a: HR = 0.54 [95% CI 0.22; 1.30], p = 0.23).
Conclusion:
In this retrospective analysis, ribociclib + NSAI + OFS demonstrated advantages across all effectiveness endpoints, including OS, in premenopausal women with HR+, HER2- early BC, without increasing overall treatment discontinuation rates compared to tamoxifen ± OFS.
Related Concept Videos
Hormonal Control of the Ovarian Cycle
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...
Treatment Resistant Cancers
Hormonal Regulation of the Menstrual Cycle
At puberty, GnRH begins a pulsatile release pattern, which triggers the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The frequency and amplitude of GnRH pulses vary across the menstrual cycle, with faster pulses favoring LH release and slower pulses favoring FSH...
Targeted Cancer Therapies
There are several types of targeted therapies against...
Cancer Therapies
However, cancer treatments can pose several challenges, as therapies used to kill cancer cells are generally also toxic to normal cells. Moreover, cancer cells mutate rapidly and can develop resistance to chemical agents or radiation therapy. Besides, all types of cancer cells may not respond to the same therapy. Some cancer cells respond to one...
Clinical Trials: Overview

