I. To compare the molecular response rates, as measured by the decrease in breakpoint cluster region-Abelson murine leukemia viral oncogene homolog 1 (BCR-ABL) transcripts after 12 months of treatment, in patients with previously untreated chronic myelogenous leukemia (CML) in chronic phase who are treated with either dasatinib 100 mg/day or imatinib (STI571, Gleevec) (imatinib mesylate) 400 mg/day.