Response and Adverse Effects of Nilotinib in Imatinib-resistant Chronic Myeloid Leukemia Patients: Data From a Developing Country

Abstract

PurposeThe purpose of this study was to determine the frequency of major cytogenetic response (MCyR) and adverse events with nilotinib in adults with imatinib-resistant Philadelphia chromosome–positive chronic myeloid leukemia (CML). MethodsThis is a descriptive cross-sectional study conducted at The Aga Khan University Hospital in Karachi from October 17, 2010, to October 17, 2011. A cytogenetic assessment using fluorescent in situ hybridization was performed on peripheral blood before initiation of treatment and 6 months after treatment with nilotinib. The frequency of adverse effects was assessed at 6 months, and the patient overall survival was calculated after 3 years. FindingsThis study enrolled 82 imatinib-resistant patients. The mean (SD) patient age was 38.9 (12.2) years. There were 62 patients (75.6%) in chronic phase, 15 patients (18.3%) in accelerated phase, and 5 patients (6%) in blast crisis phase. At 6 months cytogenetic studies were available for 40 (52%) of 77 patients, and MCyR was observed in 31 (77.5%) of 77 patients. The patients in chronic phase had the highest frequency of MCyR (n = 27 [87%] of 31). We observed 6 deaths (7.3%), and the overall survival at 3 years was 92.7%. There was isolated thrombocytopenia in 12 patients (15.6%). The most frequent nonhematologic adverse events were myalgia and headache. ImplicationsThe nilotinib response rates were higher in chronic phase patients, and the most common adverse events were thrombocytopenia, myalgia, and headache.