REAL-WORLD ADHERENCE TO RIBOCICLIB-BASED THERAPY IN HR+/HER2- ADVANCED BREAST CANCER: A RETROSPECTIVE COHORT STUDY IN ROMANIA
Author(s)
Marina Daniela Dimulescu, PhD Student1, Cristian Virgil Lungulescu, PhD1, Mihaela-Simona Naidin, BSc, MSc, PharmD, PhD1, Adina Turcu-Stiolica, PhD2.
1University of Medicine and Pharmacy of Craiova, Craiova, Romania, 2Professor, University of Medicine and Pharmacy of Craiova, Craiova, Romania.
1University of Medicine and Pharmacy of Craiova, Craiova, Romania, 2Professor, University of Medicine and Pharmacy of Craiova, Craiova, Romania.
OBJECTIVES: Ribociclib in combination with endocrine therapy is a standard treatment for hormone receptor-positive, HER2-negative (HR+/HER2−) advanced breast cancer. Real-world adherence data remain limited, particularly in Central and Eastern European settings. This study aimed to evaluate adherence patterns to ribociclib-based therapy and to compare adherence between endocrine partner regimens in a Romanian regional cohort.
METHODS: A retrospective, observational study included 203 patients with HR+/HER2− advanced breast cancer receiving ribociclib combined with either an aromatase inhibitor (AI) or fulvestrant between 2020 and 2024 in Dolj County, Romania. Data were extracted from the electronic database of the Romanian Health Insurance House, Dolj County, for the disease code 124 (Romanian health insurance system). Adherence was assessed using the medication possession ratio (MPR), with adequate adherence defined as MPR ≥0.80. Between-group comparisons were performed using the Mann-Whitney U test, with statistical significance set at p<0.05.
RESULTS: The overall mean MPR was 90.08 ± 12.95%. Of 203 patients, 173 (85.2%) achieved adequate adherence (MPR ≥0.80), while 30 (14.8%) were non-adherent. Subgroup analysis revealed comparable adherence between endocrine partners: the ribociclib plus fulvestrant group (61 patients) demonstrated a mean MPR of 92.0 ± 8.10%, while the ribociclib plus AI group (142 patients) achieved a mean MPR of 89.1 ± 13.9%. This difference was not statistically significant (p=0.595).
CONCLUSIONS: In this real-world Romanian cohort, adherence to ribociclib-based therapy was high regardless of the endocrine partner. The absence of a statistically significant difference between the fulvestrant and AI subgroups suggests that the choice of endocrine combination does not meaningfully influence adherence behavior, and that patient-related or system-level factors may play a more prominent role. The slightly lower variability observed in the fulvestrant group may reflect its administration via intramuscular injection in clinical settings, potentially reinforcing treatment regularity. These findings support proactive, regimen-agnostic adherence monitoring strategies in routine clinical practice.
METHODS: A retrospective, observational study included 203 patients with HR+/HER2− advanced breast cancer receiving ribociclib combined with either an aromatase inhibitor (AI) or fulvestrant between 2020 and 2024 in Dolj County, Romania. Data were extracted from the electronic database of the Romanian Health Insurance House, Dolj County, for the disease code 124 (Romanian health insurance system). Adherence was assessed using the medication possession ratio (MPR), with adequate adherence defined as MPR ≥0.80. Between-group comparisons were performed using the Mann-Whitney U test, with statistical significance set at p<0.05.
RESULTS: The overall mean MPR was 90.08 ± 12.95%. Of 203 patients, 173 (85.2%) achieved adequate adherence (MPR ≥0.80), while 30 (14.8%) were non-adherent. Subgroup analysis revealed comparable adherence between endocrine partners: the ribociclib plus fulvestrant group (61 patients) demonstrated a mean MPR of 92.0 ± 8.10%, while the ribociclib plus AI group (142 patients) achieved a mean MPR of 89.1 ± 13.9%. This difference was not statistically significant (p=0.595).
CONCLUSIONS: In this real-world Romanian cohort, adherence to ribociclib-based therapy was high regardless of the endocrine partner. The absence of a statistically significant difference between the fulvestrant and AI subgroups suggests that the choice of endocrine combination does not meaningfully influence adherence behavior, and that patient-related or system-level factors may play a more prominent role. The slightly lower variability observed in the fulvestrant group may reflect its administration via intramuscular injection in clinical settings, potentially reinforcing treatment regularity. These findings support proactive, regimen-agnostic adherence monitoring strategies in routine clinical practice.
Conference/Value in Health Info
2026-11, ISPOR Europe 2026, Vienna, Austria
Value in Health, Volume 29, Issue 12S
Code
PCR79
Topic
Clinical Outcomes, Patient-Centered Research, Real World Data & Information Systems
Topic Subcategory
Adherence, Persistence, & Compliance, Patient Engagement
Disease
No Additional Disease & Conditions/Specialized Treatment Areas, Oncology