Study of the prescribing and treatment outcomes of imatinib in 295 Iranian chronic myeloid leukemia patients: An eight years single institution analysis

Background: The present study investigated the patients with Chronic Myeloid Leukemia in chronic phase (CP-CML) who had been on the first- line Imatinib Mesylate (IM) therapy for a period of 84 months.Patients and Methods: This retrospective study was conducted in 295 newly-diagnosed CP-CML patients(age > 18 years )who were admitted, treatment and follow up to the Hematology, Oncology and Stem Cell Transplantation Research Center, Shariati Hospital in Tehran during the 1 January 2009 to 30 December 2016. Response to treatment was evaluated by molecular response assessment. Rates of IM dose adjustment, switching to another drug therapy, Progression to Accelerate Phase (AP) and Blastic Crisis (BC) and long-term outcomes included Overall Survival (OS) and Progression Free Survival (PFS) were assesed.Results: Patients’ average age was 41.7years, and 52.9% were male. 44.4% of patients at the month 18 achieved Major Molecular Response (MMR). Progression to AP/BC occurred in 26 patients during 84 months, and the estimated rate of OS and PFS rate were 71.83 and 74.48 respectively. Among the patients who didn’t achieve MMR at month 18 ,in 61 patient IM treatment with 400 mg /day without change treatment was continued that out of them 24 patients (39.3%) achieve MMR after month 18. Dose adjustments occurred in 60 patients (20.33%). IM dose increases were observed in 53 patients who didn’t achive optimal response to imatinib or loss of optimal response. IM dose decreases were observed in 7 patients. Switched to a different Tyrozin Kinaz Inhibitor (TKI) occurred in 25 patients (8.47%). Most of TKI changes (n=21) happened in patients who didn’t achieve optimal response to IM and for the 4 patients TKI changes were owing to adverse events of IM. among the patients undergoing change in treatment, 24(43.75%) patient achieved MMR.Among 153 patients who didn’t achieve MMR at month 18 ,in 61 patient IM treatment with 400 mg /day without change treatment was continued that out of them 24 patients achieve MMR after month 18.Conclusion: Our data showed the high effectiveness of the change in treatment in the IM resistance condition. Also our finding suggests that imatinib is effective in Iranian patients after a longer period of time compared to referenced studies.CML,Imatinib,MMR