Adherence to Tyrosine Kinase Inhibitor Therapy for Chronic Myeloid Leukemia: A Brazilian Single-Center Cohort

Abstract

The introduction of oral tyrosine kinase inhibitors (TKIs) has dramatically improved outcomes in chronic myeloid leukemia (CML) patients. However, treatment success is directly related to good long-term adherence. Adherence to TKI therapy was evaluated in 137 CML patients over a period of 1 year. Three different methods were used to evaluate adherence: the Morisky questionnaire, a medication diary and the medication possession ratio (MPR). MPR was the most effective method of assessing adherence (median adherence 96.5%; p = 0.0001), duration of TKI treatment was the variable that most impacted adherence (p = 0.03), and the MPR was inversely correlated to the duration of therapy. Additionally, participation in clinical trials, better quality of life as reported by patients and higher socioeconomic status were all related to better compliance (p = 0.02, 0.007 and 0.01, respectively). For patients treated with imatinib for 24–48 months (n = 22), individuals with major molecular response (MMR) had a significantly better MPR than those who failed to achieve MMR (p = 0.04). In this group, the mean MPR was 87% for the population without apparent molecular response and 96% for those achieving MMR; however, only 24% of the patients were completely adherent to TKI treatment.

The impact of socio‐economic factors on treatment choice and mortality in chronic myeloid leukaemia

“…Alternatively, the discrepancy between Swedish and UK data may reflect differences between patient populations. Adherence to TKI medication is vital to reduce CML mortality, and in a Brazilian study, adherence to TKI has been linked to socio‐economic status . This was also pointed out as the likely explanation of the results in the UK study .…”

“…Adherence to TKI medication is vital to reduce CML mortality, 19 and in a Brazilian study, adherence to TKI has been linked to socio-economic status. 20 T A B L E 4 Relative probability of receiving second-generation tyrosine kinase inhibitor treatment without documented prior use of imatinib among patients with chronic myeloid leukaemia in relationship to socio-economic data This was also pointed out as the likely explanation of the results in the UK study. 10 A previous study 21 indicated that poor adherence to TKIs may be less pronounced in Sweden than in the UK 22 and the USA.…”

Adherence to tyrosine kinase inhibitors among Medicare Part D beneficiaries with chronic myeloid leukemia

“…A Brazilian single-center study of patients with CML found better adherence to TKIs among patients of higher socioeconomic status. 27 A recent study by Winn et al focusing on TKI initiation within 180 days after a diagnosis of CML and subsequent TKI therapy adherence found an insignificant difference in adherence rates based on subsidy status; instead, higher initiation rates were identified for individuals with costsharing subsidies. 22 In stark contrast, the results of the current study demonstrate that despite substantially lower OOP costs for patients with LIS status, this population still had difficulty adhering to treatment with TKIs.…”

Patients' perceptions about diagnosis and treatment of chronic myeloid leukemia: a cross-sectional study among Brazilian patients

“…These nonadherent patients were more likely to fail to achieve a complete cytogenetic response and had shorter survival. 24 Among patients with CML treated with imatinib for some years, poor adherence may be the predominant reason for inability to obtain adequate molecular responses, [25][26][27] i.e. a reduction in BCR-ABL1 transcripts, or a cytogenetic response.…”