Observational Retrospective Study to Assess the Use of Ribociclib in Patients With HR+, HER2- Metastatic Breast Cancer Treated With Chemotherapy

A rEtrospectIve Real-world Analysis of earLy responsE ratEs With Ribociclib and Endocrine Therapy and Descriptive aNalysis of HR+, HER2- Metastatic Breast Cancer Patients Treated With Chemotherapy (EILEEN)

EILEEN was a non-interventional/observational, retrospective, multi-center, real life cohort study conducted in 14 private and academic oncology clinics in Turkey. Group I cohort of the study was based on secondary use of data of postmenopausal hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC) patients treated with ribociclib in combination with letrozole (LET) or fulvestrant (FUL) after June 2020. Group II cohort of the study was a parallel, comprehensive chart review for detecting all postmenopausal HR+, HER2- MBC patients who were eligible for cyclin-dependent kinase inhibitors (CDKis) but received chemotherapy. The study used secondary data which was retrieved from electronic or paper medical records or clinical databases available at the sites. Regular follow up with close monitorization was used for the effective management of patients with breast cancer. Data sources included information about diagnosis, treatment and monitorization of patients at an individual level. The study used medical patient records at hospitals e.g. hospital discharge files, primary clinical records and electronic medical records.

Study Overview

• Status: Completed
• Conditions: Metastatic Breast Cancer

• Study Type: Observational
• Enrollment (Actual): 194

Contacts and Locations

Study Locations

• United States
  • New Jersey
    • East Hanover, New Jersey, United States, 07936
      • Novartis Pharmaceuticals

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Non-Probability Sample

Study Population

This was a retrospective, noninterventional cohort study.

Description

Inclusion Criteria:

Group I: Postmenopausal female patients who had histologically or cytologically confirmed HR-positive (10% or more ER+), HER2-negative, metastatic breast cancer and initiated ribociclib combinations per local label.

• Treated with ribociclib plus letrozole relapsed after 12 months completing adjuvant treatment or without any prior endocrine treatment for metastatic disease, 1 line or less chemotherapy was allowed.
• Treated with ribociclib plus fulvestrant, clinical and/or radiological disease progression after at least 6 months and at least 1 aromatase inhibitor treatment for metastatic disease or relapsed after 12 months adjuvant aromatase inhibitor treatment and/or relapsed within 12 months completing adjuvant aromatase inhibitor, 2 lines or less prior treatments and 1 line or less prior chemotherapy at metastatic setting were allowed.
• Had first treatment response rate assessment within 6 months after ribociclib initiation.
• Initiated ribociclib in combination with letrozole/fulvestrant after MBC diagnosis after local approval of ribociclib in June 2020.

Group II: Postmenopausal female patients who had histologically or cytologically confirmed HR-positive (10% or more ER+), HER2-negative, metastatic breast cancer eligible for cyclin-dependent kinase (CDK) inhibitors according to local label but started chemotherapy.

Exclusion Criteria:

• Pre- or perimenopausal women.
• Enrollment in an interventional clinical trial for MBC during the study observation period.
• Evidence of prior treatment with any CDK4/6 inhibitor in the adjuvant setting.
• Evidence of another primary cancer within 3 years prior to the initial line containing ribociclib.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Group I; Postmenopausal female patients who initiated ribociclib combinations per local label.
Group II; Postmenopausal female patients who were eligible for cyclin-dependent kinase inhibitors (CDKis) according to local label but started chemotherapy.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall Response Rate (ORR) at First Assessment After Initiation of Treatment Combinations	Treatment combinations included ribociclib plus letrozole and ribociclib plus fulvestrant. ORR was defined as the proportion of patients with best overall response of complete response (CR) or partial response (PR) according to RECIST v1.1.	Up to 6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to Progression		Up to 3 years
Number of Patients Categorized by Former Treatment		Baseline
Number of Patients who Used Chemotherapy per Treatment Combination	Treatment combinations included ribociclib plus letrozole and ribociclib plus fulvestrant.	Up to 3 years
Progression Free Survival (PFS)	PFS was defined as the time from date of start of treatment to the date of event defined as the first documented progression or death due to any cause. If a patient did not have an event, PFS was censored at the date of last adequate tumor assessment.	Up to 3 years
Overall Survival (OS)	OS was defined as the time from date of start of treatment to date of death due to any cause. If a patient was not known to have died, survival was censored at the date of last known date patient was alive.	Up to 3 years
Time to Chemotherapy Post-ribociclib Plus Letrozole or Fulvestrant Treatments		Up to 3 years
Duration of Treatment		Up to 3 years
Proportion of Patients With Complete Response (CR)/Partial Response (PR)/Stable Disease (SD)/Progressive Disease (PD)	CR was defined as the disappearance of all non-nodal target lesions. In addition, any pathological lymph nodes assigned as target lesions must have had a reduction in short axis to less than 10 mm. PR was defined as at least a 30% decrease in the sum of diameter of all target lesions, taking as reference the baseline sum of diameters. SD was defined as neither sufficient shrinkage to qualify for PR or CR nor an increase in lesions which would qualify for PD. PD was defined as at least a 20% increase in the sum of diameter of all measured target lesions, taking as reference the smallest sum of diameter of all target lesions recorded at or after baseline. In addition to the relative increase of 20%, the sum must have also demonstrated an absolute increase of at least 5 mm.	Up to 6 months
Clinical Benefit Rate (CBR)	Clinical benefit rate: ORR and as defined by RECIST 1.1. CBR was defined as percentage of patients with complete response (CR), partial response (PR) per RECIST or stable disease (SD) lasting 24 weeks or longer.	Up to 6 months

Collaborators and Investigators

• Sponsor: Novartis Pharmaceuticals
• Investigators: Study Director: Novartis Pharmaceuticals, Novartis Pharmaceuticals

Study record dates

Study Major Dates

• Study Start (Actual): August 10, 2022
• Primary Completion (Actual): September 27, 2023
• Study Completion (Actual): September 27, 2023

Study Registration Dates

• First Submitted: September 27, 2024
• First Submitted That Met QC Criteria: September 27, 2024
• First Posted (Actual): October 1, 2024

Study Record Updates

• Last Update Posted (Actual): October 4, 2024
• Last Update Submitted That Met QC Criteria: October 2, 2024
• Last Verified: October 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Skin Diseases; Neoplasms; Neoplasms by Site; Breast Diseases; Breast Neoplasms
• Other Study ID Numbers: CLEE011ATR01