CHALLENGES OF THE TREATMENT WITH TYROSINE KINASE INHIBITORS IN CHRONIC MYELOID LEUKEMIA - CASE PRESENTATION.

We present the case of a 33-year-old male patient diagnosed with chronic phase chronic myeloid leukaemia in June 2008. According to treatment protocols enforced at that time, the patient started oral treatment with imatinib 400 mg/day, reaching a major molecular response (MMR) in 18-month time. The molecular response improved over the time, with an undetectable BCR-ABL1 transcript level after 36 -48 months of treatment. However, the profound molecular response did not last, requiring a switch to the second line of therapy after 75 months of imatinib. Taking nilotinib 400 mg x2/day, the patient achieved a major molecular response in 12 months, and after 18 months of treatment the level of BCR-ABL1 became undetectable. However, two vasooclusive events occurred in 2018 - a transient left parietal ischemic stroke and a left femoral artery occlusion - and in accordance with ESMO 2017 recommendations, nilotinib treatment was interrupted. The treatment free remission decision was made with monthly monitoring of the BCR-ABL1 transcript level, but since the 4th month of monitoring, the deep molecular response disappeared. Administration of dasatinib, the third tyrosine kinase inhibitor, resulted in a deep molecular response which currently lasted until now, during the 58 months of treatment. The presented case represents the evolution of the concept of treatment in this haemato-oncological disease during the last decade. [ABSTRACT FROM AUTHOR]