Is Adherence to Imatinib Mesylate Treatment among Patients with Chronic Myeloid Leukemia Associated with Better Clinical Outcomes in Qatar?

Abstract

BACKGROUNDDespite the revolutionary success of introducing tyrosine kinase inhibitors (TKIs), such as imatinib mesylate (IM), for treating chronic myeloid leukemia (CML), a substantial proportion of patients’ treatments fail.AIMThis study investigates the correlation between patient adherence and failure of TKIs’ treatment in a follow-up study.METHODSThis is a follow-up study of a new cohort of CML patients. Adherence to IM is assessed using the Medication Event Monitoring System (MEMS 6 TrackCap, AARDEX Ltd). The 9-item Morisky Medication Adherence Scale, medication possession ratio (MPR) calculation, and the electronic medical records are used for identifying potential factors that influence adherence. Clinical outcomes are assessed according to the European Leukemia Net 2013 guidelines via reverse transcriptase quantitative polymerase chain reaction measurement of the level of BCR-ABL1 transcripts in peripheral blood. Response is classified at the hematological, cytogenetic, and molecular levels into optimal, suboptimal, or failure.RESULTSA total of 36 CML patients (5 citizens and 31 noncitizen residents) consented to participate in the study. The overall mean MEMS score was 89. Of the 36 patients, 22 (61%) were classified as adherent (mean: 95) and 14 (39%) were classified as nonadherent (mean: 80.2). Adherent patients were significantly more likely to obtain optimal response (95%) compared to the nonadherent group (14.3%; P < 0.0001). The rate of poor adherence was as high as 39% using MEMS, which correlates with 37% treatment failure rate. The survey results show that 97% of patients increased the IM dose by themselves when they felt unwell and 31% of them took the missing IM dose when they remembered. Other factors known to influence adherence show that half of patients developed one or more side effects, 65% of patients experienced lack of funds, 13% of patients declared unavailability of the drug in the NCCCR pharmacy, and 72% of patients believed that IM would cure the disease. The MPR results reveal that 16% of patients had poor access to treatment through the hospital pharmacy.DISCUSSION AND CONCLUSIONThis is the first prospective study to evaluate CML patients’ adherence and response to IM in Qatar. The high rate of treatment failure observed in Qatar is explained by poor adherence. An economic factor (unaffordable drug prices) is one of the main causes of nonadherence and efforts should be made locally to improve access to medication for cancer diseases. Other risk factors associated with poor adherence could be improved by close monitoring and dose adjustment. Monitoring risk factors for poor adherence and patient education that include direct communication between the health-care teams, doctors, nurses, pharmacists, and patients are essential components for maximizing the benefits of TKI therapy and could rectify this problem. The preliminary results show that patients’ response to treatment may be directly linked to patients’ adherence to treatment. However, further in-depth and specific analysis...

Needs for information and reasons for (non)adherence in chronic myeloid leukaemia: Be aware of social activities disturbing daily routines

“…Other quantitative studies using a questionnaire found percentages of nonadherent CML patients ranging from 0% to 47%. 11,12,19,23,30,[34][35][36][37][38][39][40][41] Differences in the extent of nonadherence in studies are a well-known phenomenon in adherence research and relate to the drug, follow-up period and differences in measurement and calculation of adherence. 9,42 In the present study, a self-composed question was used to measure nonadherence ("How often do you not take your CML medicine?").…”

“…9,42 In the present study, a self-composed question was used to measure nonadherence ("How often do you not take your CML medicine?"). In the other studies, 11,12,19,23,30,[34][35][36][37][38][39][40][41] alternative questionnaires were used to measure medication adherence. Although the differences in measurements make it difficult to compare the results of studies, it is clear that a considerable number of CML patients have difficulties with adhering to their medication regimen.…”

“…9 Even minor deviations from the prescribed regimen may result in poor clinical outcomes, with the probability of achieving a major molecular response being significantly better in patients with an adherence rate of at least 90%. [10][11][12][13] Although measured through various methods and within different study groups, estimates of average adherence in CML vary from only 19% to almost 100% of the proportion of prescribed TKI taken. 9 Factors related to medication nonadherence are diverse and can be found in all five WHO-defined dimensions of adherence: social/ economic factors and patient-, condition-, therapy-, healthcare team and system-related factors.…”

Natural history, with clinical, biochemical, and molecular characterization of classical homocystinuria in the Qatari population

“…In our study, good adherence was defined by a Morisky score of 11 or higher (ie, ≥85%). This cutoff was selected based on previous reports . (b) Patients were asked predefined follow‐up questions to identify potential factors known to influence adherence to diet and treatment.…”

Adherence and Coping Strategies in Outpatients With Chronic Myeloid Leukemia Receiving Oral Tyrosine Kinase Inhibitors

“…When oral TKIs were introduced, given all their benefits, high adherence rates were a foregone conclusion. However, in their 15 years, adherence rates have been as low as 60% (Noens et al, 2009); other studies have revealed a similar rate of nonadherence of at least 30% (Al-Dewik et al, 2016;Lam & Cheung, 2016;Winn, Keating, & Dusetzina, 2016). Low adherence rates undoubtedly result in unfavorable sequelae (Breccia, Efficace, & Alimena, 2011;Jabbour, Kantarjian, Eliasson, Cornelison, & Marin, 2012;Santoleri et al, 2016;Wu et al, 2010).…”