Efficacy of tyrosine kinase inhibitors (TKIs) as third-line therapy in patients with chronic myeloid leukemia in chronic phase who have failed 2 prior lines of TKI therapy.

We analyzed a cohort of 26 patients with chronic myeloid leukemia who had failed imatinib and a second tyrosine kinase inhibitor but were still in first chronic phase and identified prognostic factors for response and outcomes. The achievement of a prior cytogenetic response on imatinib or on second-line therapy were the only independent predictors for the achievement of complete cytogenetic responses on third-line therapy. Younger age and the achievement of a cytogenetic response on second line were the only independent predictors for overall survival (OS). At 3 months, the 9 patients who had achieved a cytogenetic response had better 30-month probabilities of complete cytogenetic responses and OS than the patients who had failed to do so. Factors measurable before starting treatment with third line therapy and cytogenetic responses at 3 months can accurately predict subsequent outcome and thus guide clinical decisions.