The Clinical and Economic Impact of Tyrosine Kinase Inhibitor Non-adherence in CML Patients within a US Integrated Healthcare System

Document Type



Media is loading

Publication Date




J. Jackson, Jefferson College of Population Health, Thomas Jefferson University, Philadelphia PA


Background: Chronic myelogenous leukemia (CML) accounts for 15% of all adult leukemias. Oral tyrosine kinase inhibitors (TKIs) have improved long-term survival significantly, but require strict adherence to the therapy to maximize effectiveness and minimize healthcare resource utilization.

Objective: To evaluate adherence to tyrosine kinase inhibitor therapy for incident CML patients, assess predictive factors associated with TKI non-adherence, evaluate laboratory monitoring rates and clinical response between adherent and non-adherent patients, and to compare healthcare resource utilization and costs between these groups.

Methods: Retrospective, observational cohort study using databases from the Kaiser Permanente health plan. Newly diagnosed CML patients were identified from 1/1/2007-12/31/2013 with index date as first incident TKI prescription fill. Adherence rates were measured over the 12-month post-index period using the MPR method, with an adherence threshold set at ≥85%. Patient characteristics and covariates were evaluated as potential contributors to non-adherence included age, gender, race, existing comorbidities, and healthcare utilization history. Laboratory monitoring included either hematologic, cytogenetic, or molecular testing during the post-index period. Clinical response/remission or no clinical response/progression was evaluated at the end of the 12-months and compared between the adherent and non-adherent groups. All-cause and CML-related healthcare resource utilization and costs were compared between the two groups as well.

Results: 194 CML patients were selected for inclusion into this study. Of the 194 patients, 123(63.4%) were found to be adherent to TKI therapy. Patient age, Deyo-Charlson Comorbidity index, pre-index hospitalization length of stay, and oral antidiabetic and antihyperlipidemic medications were found to be predictive factors associated with non-adherence. Adherent patients were more likely to be adherent to hematologic (100% vs 95.8%) and molecular/cytogenetic testing (91.1% vs 76.1%) than non-adherent patients. Of the 123 adherent patients, 106 (86.2%) achieved clinical response at the end of 12 months, compared to only 3 of the 71 (4.2%) non-adherent patients. Adherent patients had more all-cause and CML-related outpatient visits. Non-adherent patients had more all-cause and CML-related ER and hospital visits, higher hospitalization costs, and higher total mean costs.

Conclusion: The results confirm the importance of adherence to TKI therapy on clinical outcomes, healthcare resource utilization, and costs.

Presentation: 36:18

This document is currently not available here.