Clinical impact of dose intensity of initial tyrosine kinase inhibitor (TKI) therapy in accelerated-phase CML (CML-AP).

6587 Background: For patients (pts) presenting with CML-AP, TKIs are recommended. Although generally well tolerated, dose reductions and/or interruptions are often required. The impact of TKI dose intensity (DI) on CML-AP outcome has not been described. Aim: To determine impact of TKI dose interruptions and/or reductions on outcome in de novo CML-AP. Methods: Overall, 58 CML-AP pts (median age 46 yrs) were treated on consecutive or parallel clinical trials with TKIs as initial therapy: imatinib (n=36), dasatinib (n=5), or nilotinib (n=17). CML-AP features included: blasts ≥15% (n=8), basophils ≥20%, (n=22), platelets 1 feature (n=3). We examined the impact of dose reductions, treatment interruptions, and DI (ratio of the dose received vs. the intended dose for the entire treatment duration) on event-free (EFS), transformation-free (TFS), and overall survival (OS). Results: Among 58 pts, 37 required treatment interruptions and/or dose reductions (2...