After 2 1/2 years on 400 mg Gleevec (and reaching PCRU). The bone pain was significantly increasing in frequency and intensity. My oncologists would not agree to lower the dosage of Gleevec but did agree to switch me to Tasigna a month ago. The side effects I am experiencing on the Tasigna are much less. The bone pain has been negligible and no GI or nausea issues. The first 10 days or so felt like the flu and then I had a rash and itching which has dissipated. I wish I had made the change earlier!