Use patterns of first-line inhibitors of tyrosine kinase and time to change to second-line therapy in chronic myeloid leukemia.

Background Chronic myeloid leukemia (CML) has a low incidence but a high burden of disease, and is treated with high-cost tyrosine kinase inhibitors (TKI). Objective To determine the time from the start of a first-line TKI until it passes to second-line, and to establish the reasons for the change of therapy time. Setting Patients with Philadelphia-positive CML treated with some TKI. Methods Retrospective cohort study, between January 1 2007 and July 31 2015, with information obtained from medical records, the time to change initial drugs to secondline therapy, and the reasons for change, were identified. Kaplan-Meier survival analysis was carried out. Main outcome measure A change in therapy to the secondline TKI and the final reason for the change of therapy. Results A total of 247 patients treated were found in 22 cities in Colombia with a mean age of 53.2 ± 15.2 years. The drug most used as initial therapy was imatinib; 53.8% of cases had to change to another TKI. 50% of patients changed therapy in 42 months, men in 24 and women in 67 months (95% CI 14.314-33.686; p = 0.001). Being male (OR 2.23; 95% CI 1.291-3.854; p = 0.004) and receiving hydroxyurea (OR 3.65; 95% CI 1.601-8.326; p = 0.002) were associated with a higher probability of switching to nilotinib or dasatinib, while receiving a new-generation TKI (OR 0.15; 95% CI 0.071-0.341; p < 0.001) reduced this risk. Conclusions A high proportion of patients needed to change to a second line with nilotinib and dasatinib management. It is necessary to obtain more real world evidence, to improve the effectiveness, adherence and safety of the treatment.