Krishna Deo Sharma, Chandra Bhushan Jha, Prahlad Karki, Ajaya Jang Kunwar, Sunil Dhungel, Dhiraj Maskey
ABSTRACT
Background: The cause of chronic myeloid leukemia (CML) is the Philadelphia (Ph) chromosome formed by a reciprocal translocation between chromosomes 9 and 22 giving rise to a constitutively active BCR-ABL tyrosine kinase. Imatinib Mesylate inhibits this kinase in newly diagnosed chronic phase chronic myeloid leukemia. The aim of this study was to evaluate the cytogenetic response of Imatinib Mesylate in Nepalese chronic myeloid leukemia patients in chronic phase.
Methods: Fifty clinically diagnosed and hematologically proven chronic myeloid leukemia patients in chronic phase were selected for cytogenetic analysis at the time of diagnosis. Philadelphia chromosome positive patients received Imatinib Mesylate 400 mg orally daily. The follow up cytogenetic analysis was done to monitor the size and progression of the Philadelphia positive clone.
Results: After median follow up of 13 months of Imatinib therapy 3 patients (10%) had complete (0% Philadelphia positive metaphases), 18 patients (60%) had partial (1% to 35% Philadelphia positive metaphases), and 7 patients (23%) had minor (36% to 65% Philadelphia positive metaphases) cytogenetic responses while 2 patients (7%) showed no cytogenetic response (more than 95% Philadelphia positive metaphases at all points and increase in Philadelphia positive metaphases).
Conclusion: Major cytogenetic response of Imatinib Mesylate was found in 70% of chronic myeloid leukemia patients in chronic phase; complete cytogenetic response only in 10%. The important causes for these suboptimal results of Imatinib therapy would be unavailability of patients at regular follow up due to financial constraints, unavailability of the diagnostic facility in the country and drug dose adjustment.
Keywords: Chronic Myeloid Leukemia, Philadelphia Chromosome, Imatinib mesylate.