An observational study in Advanced Breast Cancer, sponsored by Shirley Vichy Wang. Completed at 1 site in United States. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-12.
Sponsored by Shirley Vichy Wang · Observational
Investigators are building an empirical evidence base for real world data through large-scale emulation of randomized controlled trials. The investigators' goal is to understand for what types of clinical questions real world data analyses can be conducted with confidence and how to implement such studies.
Randomized controlled trials (RCTs) are generally regarded as the gold-standard of evidence for establishing efficacy of medical products. However, real-world data (RWD) are increasingly used to complement evidence from RCTs. Yet, to have confidence in the accuracy of non-interventional studies medical products and their outcomes in oncology, investigators need to know what questions can be validly answered, with which non-interventional study designs, and which analysis methods are appropriate, given the data that is available. Building on a process from the RCT DUPLICATE initiative1-4 EmulatioN of Comparative Oncology trials with Real-world Evidence (ENCORE) is part of the expansion project specific to oncology and aims to emulate 12 randomized oncology RCTs using multiple EHR data sources.
The purpose of this protocol is to describe the emulation of the MONALEESA-2 trial. MONALEESA-2 was a Phase III, double-blind, randomized study assessing the efficacy and safety of ribociclib (600 mg orally once daily on days 1-21 of a 28-day cycle, followed by 7 days off) in combination with letrozole (2.5 mg orally once daily, continuously) versus letrozole alone in postmenopausal women with hormone receptor-positive [estrogen receptor (ER) and/or progesterone receptor (PR)], human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer who had not received prior systemic treatment for their advanced disease.
This is the only study on the registry with Shirley Vichy Wang as lead sponsor.
Counted across the registry records on this site, refreshed daily.
Postmenopausal women with hormone receptor (HR)-positive [estrogen receptor (ER) and/or progesterone receptor (PR)], human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer.
Study Period:
ENCORE database 1 (EDB1): Patient identification period: 01/01/2011-04/30/2024 with follow-up information through data cut-off date on 04/30/2024 ENCORE database 3 (EDB3): Follow-up information through June 2023 (there is no specific time period restrictions for patient eligibility) ENCORE database 4 (EDB4): Patient identification period: 10/01/2018-09/30/2023 with follow-up information through data cut-off date on 09/30/2023.
Inclusion Criteria:
Exclusion Criteria:
Exposure group
Drug: Initiation of ribociclib
Reference group
Drug: Initiation of ribociclib · Drug: Initiation of letrozole
Initiation of ribociclib plus letrozole described in electronic health records is used as the exposure
Initiation of letrozole described in electronic health records is used as the reference
Time to all-cause mortality/overall survival (OS)
Hazard ratio (95% CI)
Time frame: From time of initiation of therapy through the earliest of death from any cause (the primary outcome of interest) or end of data availability (depending on specialty oncology registry data provider, end of data ranges from June 2023 to April 2024)
Documents are hosted by the registry — open the source record to download them.
This study is completed, as verified in Nov 2025. You cannot join it, but the record below documents what was studied.
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