OBJECTIVES: Chronic myeloid leukemia (CML) is a progressive disease consisting of three phases: chronic, accelerated and blast crisis. Imatinib achieves high response rates and improves prognosis. Dasatinib is a BCR-ABL kinase inhibitor approved for treating CML across all phases of disease. The present study modeled the time to response, time to accelerated phase, blast crisis and death of newly diagnosed patients with CML receiving first line therapy with dasatinib 100 mg/day or imatinib 400 mg/day in the chronic phase. METHODS: A Markov simulation model was developed using two cohorts of 200,000 CML patients treated with dasatinib 100 mg/day or imatinib 400 mg/day. Health states included were complete cytogenetic response (CCyR), major cytogenetic response (MCyR), no-response, transformation to accelerated phase or blast crisis and death. A 5-year time horizon was considered. Each 3 months the patient faces a probability of staying in the same health state or moving to a next state. Transition to death is possible from all health states. This model was populated with efficacy data from clinical trials and different times to events were modeled using Weibull regression techniques. RESULTS: The Weibull model for the time to response and time to transformation to accelerated phase and blast crisis showed significant differences between treatment groups. The model coefficient indicated that the chance of response was higher in dasatinib patients with a difference of 12.54% versus imatinib. Patients receiving imatinib had 1.57% higher chance of moving to the accelerated phase and blast crisis earlier. Time to death did not differ significantly between treatments. CONCLUSIONS: The analysis showed earlier responses and a lower chance of reaching the accelerated phase and blast crisis faster with dasatinib 100 mg/day over imatinib 400 mg/day. Results were obtained according to the assumptions used but will need to be validated by future patient level data.