Real-world study of imatinib treatment patterns and outcomes among veteran patients with chronic myeloid leukemia.

6600 Background: Imatinib (IM) is the most commonly used drug in the treatment of chronic myeloid leukemia-chronic phase (CML-CP) patients (pts). This study investigated the treatment patterns and outcomes for veteran CML-CP pts initiated on IM. Methods: Pts (age >18 yrs) with >1 CML diagnosis codes documented (ICD-9 CM: 205.1x) between 1/1/2000 and 12/31/2010 were identified from the VISN 16 data warehouse. Pts were required to have initiated IM as the first-line therapy in CML-CP. Accelerated and blastic phases (A/BP) were identified based on WHO classification using CBC information. IM dose adjustments were assessed as dose increase from 600mg or from 400-600mg to >800 mg daily. Rates of IM discontinuation (no use of IM for >60 days) and switching to other drug therapy (dasatinib/nilotinib (DS/NL), hydroxyurea, and interferon-alpha) were estimated. Time to discontinuation, progression to A/BP, and survival were assessed using Kaplan-Meier analysis (K-M). Overall survival was measured from I...