2. Any prior treatment for CML with: any tyrosine kinase inhibitor (eg imatinib, dasatinib); busulphan; interferon-alpha; homoharringtonine; cytosine arabinoside; any other investigational agents (hydroxycarbamide and anagrelide are the only drugs permitted). NB patients will be ineligible for the study if they have received ANY prior therapy with interferon-alpha or imatinib. NO exceptions.