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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)

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT06619704
Enrollment
194
Registered
2024-10-01
Start date
2022-08-10
Completion date
2023-09-27
Last updated
2024-10-04

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Metastatic Breast Cancer

Brief summary

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.

Interventions

None listed

Sponsors

Novartis Pharmaceuticals
Lead SponsorINDUSTRY

Study design

Observational model
COHORT
Time perspective
RETROSPECTIVE

Eligibility

Sex/Gender
FEMALE
Age
18 Years to No maximum

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.

Design outcomes

Primary

MeasureTime frameDescription
Overall Response Rate (ORR) at First Assessment After Initiation of Treatment CombinationsUp to 6 monthsTreatment 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.

Secondary

MeasureTime frameDescription
Number of Patients who Used Chemotherapy per Treatment CombinationUp to 3 yearsTreatment combinations included ribociclib plus letrozole and ribociclib plus fulvestrant.
Progression Free Survival (PFS)Up to 3 yearsPFS 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.
Overall Survival (OS)Up to 3 yearsOS 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.
Time to ProgressionUp to 3 years
Number of Patients Categorized by Former TreatmentBaseline
Duration of TreatmentUp to 3 years
Proportion of Patients With Complete Response (CR)/Partial Response (PR)/Stable Disease (SD)/Progressive Disease (PD)Up to 6 monthsCR 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.
Clinical Benefit Rate (CBR)Up to 6 monthsClinical 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.
Time to Chemotherapy Post-ribociclib Plus Letrozole or Fulvestrant TreatmentsUp to 3 years

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026