How we monitor the therapy effectiveness in patients with chronic myeloid leukemia - A Single center experience

Chronic myeloid leukemia (CML) is a hematological disorder characterized by increased proliferation of the granulocytic cell lineage. We diagnose CML by presence of the breakpoint cluster region-abelson (BCR-ABL1) oncogene using the quantitative real-time polymerase chain reaction (QRT-PCR). This method provides an accurate and unambiguous follow-up of the treatment response to tyrosine kinase inhibitors (TKIs). This study aimed to determine the molecular response to the first and second generation of TKIs in first and second line of treatment using the QRT-PCR method. We conducted a retrospective study on 48 CML patients treated with the first and second generation of TKIs in first and second-line treatment. Treatment responses have been followed-up every 3 months using the QRT-PCR method. Patients were divided into three groups according to molecular responses to the first line of TKIs. Results obtained in this study showed that the first group of patients did not achieve major molecular response (MMR) in the first 18 months of TKI treatment. The second and third group of patients achieved MMR and deep molecular response (DMR) in the first 18 months of TKI treatment. These results indicate that patients with MMR and DMR in the first 18 months of TKIs treatment had a favourable clinical course of the disease. Inadequate molecular responses to the first line of TKIs can be improved with in increase of the dose of TKIs or by switching to other TKIs. Continuous and timely molecular monitoring of TKI’s response in CML patients provides a careful observation of the disease's course and a proper treatment approach.