How long before white cells start to decrease after starting dasatinib
Posted 09 November 2015 - 01:37 PM
My doc is a little anxious but has scheduled me for Thursday.
My question relates to should dasatanib be working after 6 daily doses. At what point do we look to change therapies
Thanks for sharing your experience
Posted 09 November 2015 - 02:20 PM
Welcome. This will sort out over time. 6 doses is not nearly enough to see results since these drugs work somewhat indirectly. You need a month or so to see how things start out.
More to the point, what you are experiencing is part of the problem with using Hydroxyurea (HU) as the starting drug. It causes a yo-yo effect with the WBC so the next several weeks will not tell the true story. And your Onc apparently does not understand this, so let me explain.
Starting with HU kills off a large number of blood cells indiscriminately, whether leukemic or good cells. The good blood cells are already struggling, so knocking them back is not a good idea. The leukemic cells recover faster than the normal cells, and the upward bounce can be dramatic, since the HU actually enhances the leukemic WBC rebound to some degree. Starting with the Sprycel TKI drug directly results in a much more controlled descent in WBC. This is preferable.
But you are where you are, and this has happened many times to others. As I said at the start, this will sort out over time. The TKI drug should start showing a more controlled descent in leukemic cells over the next several weeks. But don't let your Onc give you any more HU under any circumstances. And don't let a confused Onc scare you. Let the Sprycel do its work.
Just as a side point, there are a very few who do not see results from Sprycel because of a specific mutation called T315i. Although it is unlikely you have this, it would become apparent over the next couple months if the Sprycel does not work at all. A test can reveal this mutation. But again, this scenario is unlikely. Just pointing this out in case your Onc happens to mention it.
So take the Sprycel for a month and see how it goes. As I said, these drugs work somewhat indirectly, so they take longer than a few days to see results. But the drugs do work quickly enough to see results in about a month or so.
Don't let your Onc panic you. He does not understand HU or he would not have used it. Don't take any more HU !!!!! Let the Sprycel do its work. If he insists on more HU, run out and find another Onc very, very quickly.
Posted 09 November 2015 - 03:18 PM
I was put on HU at diagnosis (106k WBC). It took my numbers so far down I had to wait to start TKI's for 2 weeks after stopping HU. My WBC went back up from 3k to 6k the next week to 30k by the second week. I started Sprycel 100mg that 2nd week and my numbers came down slower over the following month until I hit around 3k and stayed there for awhile. Now my normal is around 4-5k.
It's hard not to panic, but listen to Trey. I wish I would have found this discussion group before I was put on HU.
7/2014 Diagnosed,8/14 Started 100mg Sprycel, 9/14 Thyroidectomy (thyroid cancer)
8/2015 Undetectable, 12/15 Plural Effusion (3 wk drug break)
1/2016 Started 70mg Sprycel, 3/16 Plural Effusion (4 wk drug break)
3/16 .014 after a wk w/o meds
4/16 Started 400mg Gleevec
4/16 Undetectable, 7/16 Undetectable, 10/16 Undetectable, 2/17 Undetectable, 5/17 Undetectable, 8/17 Undetectable
Posted 12 November 2015 - 03:01 PM
Thanks for the replies- they helped!
The white cell count has started to decrease. That was a week and half after starting the dasatinib.
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