1. Patients age 15 years or older with a diagnosis of Ph-positive or Bcr-positive CML in chronic phase CML. They should be in at least one of the categories below: A. Patients must have received interferon alpha and: - Failed to achieve or lost a hematologic complete remission(after 3 months of therapy with interferon), or - Failed to achieve or lost a major cytogenetic remission, or - Failed to achieve or lost a complete molecular remission (competitive quantitative PCR <0.05%), or - Were intolerant to interferon B. Patients in late chronic phase (i.e., >/= 12 months from diagnosis) who have not received treatment with interferon and: - Have high risk for toxicity with IFN-A (e.g., age >/= 60 years), or - Refuse to use IFN-A