1. Chronic phase patients must have failed therapy with Gleevec. Failure will be defined as: (i) Patients who have not achieved or have lost their hematologic response at 3 months from the start of therapy with Gleevec, or (ii) Patients who have not achieved or have lost their cytogenetic response after 6 months of therapy with Gleevec, or (iii) Patients who have not achieved or have lost their major cytogenetic response after 12 months of therapy with Gleevec.