Dasatinib compared to imatinib (IM) in patients (pts) with newly diagnosed chronic-phase chronic myelogenous leukemia in chronic phase (CML-CP): Twelve-month efficacy and safety from the phase III DASISION study.

LBA6500 Background: Dasatinib is a highly potent BCR-ABL kinase inhibitor. Once daily dasatinib demonstrated high rates of durable complete cytogenetic response (CCyR) with 73% progression-free survival and 87% overall survival at 3 yrs in pts with CML-CP post IM failure. DASISION compares efficacy and safety of dasatinib and IM as initial treatment of CML-CP. Methods: 519 pts with Ph(+) newly diagnosed CML-CP stratified by Hasford risk were randomized to dasatinib 100 mg QD (n = 259) or IM 400 mg QD (n = 260). The primary endpoint was 12-mo rate of confirmed CCyR (cCCyR; CCyR on 2 consecutive analyses; any # of metaphases). Other endpoints were rates of and times to CCyR and major molecular response (MMR). Results: Pts characteristics were well balanced. Minimum follow-up was 12 mos; median treatment duration was 14 mos. 85% of dasatinib and 81% of IM pts remained on study. Median dose intensity was 99 mg/d for dasatinib and 400 mg/d for IM. cCCyR rate was superior for dasatinib vs IM (77% vs 66%, P = 0....