Hello Rajesh,
David has already put a higher than average WBC's into the context of infections etc. In the context of your treatment with 400mg imatinib at almost 3 months from start of therapy, your WBC should be at the normal range which would be around 4- 12. As your white cells are hovering around 15 to 16.5 at the 3month stage it may be that you have an infection and they will start to reduce to normal range over the next week or so. However, it may also be that imatinib at 400mg is not enough to effect an optimal response in your case.
I assume your were diagnosed in chronic phase?
According to ELNet recommendations which you can find on our Resources page, at 3 months (90 days) from starting TKI therapy, for an 'optimal response' you should expect to have achieved at least a partial cytogenetic response (PCyR) which is at or below 35% Ph+ cells, or more optimally less than 10% Ph+ cells. This would be measured by a test called a Q-PCR test.
See the link below for a table of the timelines and treatment goals you should expect to reach:
http://www.leukemia-net.org/content/leukemias/cml/recommendations/e8078/...
I am not sure if you have access to the Q-PCR molecular test but if not you should ask your doctor what kind of tests he/she is using to assess your response to therapy in order to see if you are reaching the correct treatment milestones. Current TKI treatment goals should see a significant reduction in PH+ cells from 100% down to below 1% by 6 months and 0.1% or below by 12 months.
You should ask your doctor why your white cells are still above normal range and also whether you have had tests to see if you have had a cytogenetic response (CyR). If your doctor agrees that you have not yet had a cytogenetic response and your PH+ cells are still at or around 100%, then ask if you can have a mutational analysis for a possible imatinib resistant mutation which may be the causing your lack of response to 400mg imatinib. However, if you do not have an imatinib resistant mutation and there is no other cause identified for your lack of response at 3 months, then ask if you can either increase your dose to 600mg or change to a 2nd generationTKI such as dasatinib, bosutinib or nilotinib.
Sandy