A Phase IIb Study of Molecular Responses to Imatinib, at Standard or Increased Doses, or Dasatinib (BMS-354825) (NSC-732517) for Previously Untreated Patients With Chronic Myelogenous Leukemia (CML) in Chronic Phase.

Pts must have a diagnosis of CML in chronic phase based on bone marrow aspiration and biopsy and peripheral blood counts obtained within 28 days before registration. Pts must be registered within 180 days after first being diagnosed with CML, based on cytogenetic or molecular analysis demonstrating the presence of Philadelphia chromosomes or variants of the (9;22) translocation or testing positive for Bcr-Abl by RT-PCR. Pts may have had secondary chromosomal abnormalities in addition to the Philadelphia chromosome. Pts must have reached their 18th birthdays. Zubrod PS of 0-2. Pts must not have received prior treatment for CML with the exception of hydroxyurea and/or anagrelide. Pts must not have received any prior chemotherapy regimen for peripheral blood stem cell mobilization. Pts must have a serum bilirubin, and SGOT/AST or SGPT/ALT< all less than or equal to 2.0 x the IULN within 14 days prior to registration. Pts (SWOG institutions only) must be registered on SWOG-9007, "Cytogenetic Studies in Leukemia Patients." Pts (SWOG institutions only) must be registered on S9910, "Leukemia Centralized Reference Laboratories and Tissue Repositories, Ancillary." Pts must not have undergone major surgery within 28 days before registration, and must have fully recovered from any other prior major surgery. Pts must have an ECG within 42 days before registration and must not have the cardiac symptoms listed in Section 5.13. Pts must not have a history of significant bleeding disorder unrelated to cancer. Pts must not be pregnant or nursing. Women/men of reproductive potential must have agreed to use an effective contraceptive method. No other prior malignancy is allowed except for the following: adequately treated basal cell or squamous cell skin cancer, cervical carcinoma in situ, adequately treated Stage I or II cancer from which the pt is currently in complete remission, or any other cancer from which the pt has been disease-free for five years.