[Response to treatment with tyrosine kinase inhibitors in chronic myeloid leukemia]

Chronic myeloid leukemia represents 15 % of all the leukemias in adults. With the introduction of tyrosine kinase inhibitors, overall survival at 10 years is 80-90 %. The objective was to describe the epidemiology, complete cytogenetic response and major molecular response with tyrosine kinase inhibitors in patients with chronic myeloid leukemia.

It was performed a descriptive cross-sectional study of patients with chronic myeloid leukemia and Philadelphia chromosome-positive in treatment with tyrosine kinase inhibitors.

The sample included 54 patients with a mean age of 41 years; 78 % of patients were in chronic phase, and in 8 % of patients were identified complex karyotype at diagnosis. All patients received imatinib as first-line treatment. We identified mutations in 8 %. The patients with primary or secondary resistance (30%) received second-generation tyrosine kinase inhibitors as a second-line therapy. Of 35 patients treated with imatinib, 23 had complete cytogenetic response, 23 had major molecular response, and 16 had loss of response to treatment. Of nine patients treated with nilotinib, two presented complete cytogenetic response, two major molecular response, and five loss of response to treatment. Of seven patients treated with dasatinib, two had complete cytogenetic response, two major molecular response, and four loss of response to treatment.

Of patients studied, 30 % was resistant to imatinib, 52 % achieved a complete cytogenetic response, and 42 % major molecular response. The use of second generation tyrosine kinase inhibitors led to obtain a complete cytogenetic and major molecular response in fewer time.