[Background] Some tyrosine kinase inhibitors (TKIs) are effective in the treatment of chronic-phase chronic granulocytic leukemia (CML-CP). The investigators analyzed the long-term molecular and cytogenetic remission and survival prognosis of four TKI’s as first-line therapy for CML-CP. [Methods] In this retrospective analysis, the investigators included data from patients with CML-CP treated with first-line TKI in clinical trials from July 31, 2000-September 10, 2013. The primary objective of this study was to determine whether achieving complete cytogenetic remission or major molecular remission had the same prognostic significance without regard to the first-line TKI used. The investigators analyzed remission assessments for each TKI modality and used Kaplan-Meier analysis for survival endpoints (event-free, failure-free, transformation-free and overall survival). Cox proportional risk regression was used for univariate and multivariate analyses. [Results] This analysis included 482 patients who were treated with 400 mg/day imatinib (n=68), 800 mg/day imatinib (n=200), 50 mg/day twice or 100 mg/day dasatinib (n=106) or 400 mg/day twice nilotinib (n=108). Among patients receiving 800 mg of imatinib or second-generation TKIs (eg, dasatinib or nilotinib), complete cytogenetic remission was achieved (87% [58/67] 400 mg imatinib vs. 90% [180/199] 800 mg imatinib vs. 96% [100/104] dasatinib vs. 93% [99/107] nilotinib) and A higher proportion of patients in major molecular remission (51 [76%] vs. 171 [86%] vs. 93 [90%] vs. 97 [91%]). bcr-abl transcript reduction ≥4?5log (MR4?5 remission 38 [57%] vs. 148 [74%] vs. 76 [71%] vs. 76 [71%]). This result did not change with increasing time (3C60 months). 5-year event-free survival in the 400 mg imatinib group was significantly different from the other TKI groups (800 mg imatinib p=0.029, dasatinib p=0?003, nilotinib p=0.031). 5-year failure-free survival (p=0.32,p=0.075, p=0.332 ), non-transformed survival (p=0.053, p=0.038, p=0.493) or overall survival (p=0.563,p=0.162, p=0.981) were not significantly different. Multivariate analysis showed that 800 mg imatinib (HR 0.51, 95% CI 0.29C0.88, p=0.016), dasatinib (0.28, 0.12C0.66, p=0.004) or nilotinib (0.42,0.20C0.89, p=0?024) predicted better event-free survival compared with 400 mg imatinib. However, failure-free survival, transformation-free survival and overall survival were similar. 28 (41%) patients receiving 400 mg imatinib, 85 (43%) patients receiving 800 mg imatinib, 23 (21%) patients receiving dasatinib and 27 (25%) patients receiving nilotinib discontinued treatment. [Interpretation] Receiving 800 mg of imatinib or the second-generation TKIs dasatinib or nilotinib resulted in superior remission than receiving standard-dose imatinib, and this advantage was maintained after 5 years of follow-up. The results were similar for 800 mg imatinib versus second-generation TKIs, despite the higher number of patients who interrupted treatment.