6 weeks ago I changed from 400g Imatinib to 800 g Nilotinib as I had stopped responding (resistance) and my 10 months PCR since diagnosis had gone up to 28%. I am happy to say that despite a treatment break and reduced dosage for 3 weeks due to side effects, my latest PCR has come back today and it is 9.8%. It is great how quick the new medicine has worked.