Evaluation of Treatment Outcomes of Patients with Chronic Phase Chronic Myelogenous Leukemia (CML) to Imatinib: A Single Centre Experience 2010-2015 Period

Background: Chronic myelogenous leukemia (CML) is a myeloproliferative neoplasm that accounts for approximately 15% of newly diagnosed cases of leukemia in adults. The incidence of CML has increased two-fold from 1241 to 2517 cases from 1970 -2017. Tyrosine kinase inhibitor, such as Imatinib, is the first-line treatment of chronic phase CML that efficiently inhibits the BCR–ABL1 kinase. Treatment response can be evaluated by measuring the Complete Hematologic Response (CHR) and Major Molecular Response (MMR). We aim to evaluate the treatment outcomes of chronic phase CML patients to Imatinib and their characteristics. Materials and Methods: We collected data retrospectively from medical records of newly diagnosed chronic phase CML patients from 2010 to 2015 period at Dr. Cipto Mangunkusumo General Hospital, Jakarta, Indonesia, regarding age, gender, symptoms, splenomegaly, complete blood count, BCR-ABL variant transcript, Sokal and ELTS scores, last treatment, Complete Hematological Response (CHR), Major Molecular Response (MMR), and their last phase. Association between patient characteristics and treatment response was evaluated. Results: Out of 60 patients with CML, the median age was 43 years (24-72), including 36 (60%) men and 24 (40%) women. There were 46 (76.7%) patients with symptoms and 14 (23.3%) patients without symptoms. Splenomegaly was found in 42 (70%) patients. BCR-ABL transcript variant of b2a2 was the most frequent (51.7% of patients). Intermediate-high risk patients outnumber low-risk patients. CHR was found in 44 (74.6%) patients while MMR was found in 16 (33.3%) patients. There were 51 (85%) patients who remained in the chronic phase while 9 (15%) patients progressed to the accelerated phase. CHR was significantly different between low and intermediate-high risk Sokal score group (p=0.025) and MMR was significantly different between leukocytosis more than 100.000/µL, vs leukocytosis less than 100.000/µL (p=0.001) and low vs intermediate-high risk ELTS score group (p=0.038. Conclusion: The median age of our chronic phase CML patients was similar to the other Asian countries. We had poorer treatment response which might be related to a high number of intermediate-high risk patients and delays in diagnosis.