Objetive: The aim of this study was to identify the reasons for failure in adherence to imatinib mesylate treatment in chronic myeloid leukemia. Methods: A retrospective review was performed of 100 non-electronic records of patients with Ph+ chronic myeloid leukemia treated with imatinib mesylate. The study period was from January 2001 to January2011. Data were analyzed by Chi-Square and Correspondence analysis using the Statistical Analysis System software package. Results: At the beginning of treatment 41% of patients were in advanced stages of the disease. The unavailability of the drug (44.8%) and myelotoxicity (25.7%) were the most frequent reasons for interruption. The adherence rate was < 90% in 47% of the cases. The low adherence influenced the cytogenetic response (p-value = 0.020) and molecular response (p-value = 0.001). Very high adherence (> 95%) induced complete cytogenetic response, major cytogenetic response and major molecular response. Conclusion: The population of this study obtained lower-than-expected therapeutic responses compared to other studies.

Background: In the last decade, there has been a revolution in chronic myeloid leukemia treatment with the introduction of tyrosine kinase inhibitors with imatinib mesylate becoming the frontline therapy. Objective: To evaluate the therapeutic efficacy of imatinib mesylate in treating chronic myeloid leukemia patients and to identify factors related to therapeutic efficacy. Methods: This retrospective study was based on information obtained from patients'records in the Hematology Service of Hospital Universitário Walter Cantídio of the Universidade Federal do Ceará (HUWC / UFC). All patients diagnosed with chronic myeloid leukemia that took imatinib mesylate for a minimum of 12 months in the period from January 2001 to January 2011 were included. From a population of 160 patients, 100 were eligible for analysis. Results: The study population consisted of 100 patients who were mostly male (51%) with ages rangingbetween 21 and 40 years (42%), from the countryside (59%), in the chronic phase (95%), with high-riskprognostic factors (40%); the prognosis of high risk was not associated with complete hematologic responseor complete cytogenetic response, but correlated to complete molecular response or major molecularresponse. Reticulin condensation was associated with complete hematologic response and completecytogenetic response. It was found that 53% of patients had greater than 90% adherence to treatment. Thehigh adherence was correlated to attaining complete cytogenetic response in less than 12 months. Moreover,20% of patients had good response. Conclusion: Significant changes are indispensable in the monitoring of patients with chronic myeloid leukemia. Thus, the multidisciplinary team is important as it provides access to the full treatment and not just to medications.