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sub-optimal response at 6 months

I've just received the results of my PCR at 6 months - still 16% - it was 19% at 3 months and 11% at 4 and 1/2 months. the FISH results on the BM were 3% (100% at diagnosis but negative at 3 months). I'm on Nilotinib 600mg since diagnosis and, apart from a brief interruption due to low blood count, I have not missed a dose.
My consultant seemed rather concerned - she's requested a mutational analysis and she thinks it will be necessary to change to another TKI - it's going to be either Dasatinib or Ponatinib....somehow the choice does not look so good anymore! In a way I would prefer to stay on Nilotinib for a bit longer (better the devil you know!) - I know that the 6 months results are an important milestone and the time to evaluate how well the therapy is working. I have also read lots of scientific papers and know perfectly well that the long term outcome for patients that don't reach CCyR and MMR at 6 months is not good. I'm clearly not a textbook case (who is?) and I hope that, perhaps, I need just a bit longer to see a significant drop in my PCR.
My blood test is OK, probably better than it's been for a while and, as usual, I feel absolutely fine

Hi Louisa,
first: FISH only tests around 200 cells so that would explain your negative by FISH at 3 months.
Your 6 mth Q-PCR shows your still have a significant % or BC-ABL transcripts (although unless you are at or below CCyr -1.5% BCR-ABL- then Q-PCR is not completely accurate either. Your results would depend on how good the control sample was. Nevertheless, from the published NCCN and ELNet gudelines/recommendation on this issue, I am not surprised that your consultant wants to be proactive.
If on further testing a mutation of some kind does show up, then the next move for you would depend on which mutation that might be. Some are best treated with dasatinib, others with nilotinib. As I am sure you are aware, ponatinib is the only TKI that is effective when the T315i mutation is evident. In England (rather than in Scotland/Wales/N.Ireland) ponatinib is only available through the CDF (cancer drugs fund) and only for patients with T315i.

Dasatinib has proven to be a very effective alternative for a significant number of patients and many on this forum have responded very well to that TKi.

Of course there is also bosutinib- again available on the CDF- which for some has proven to be a very good alternative indeed.

Given that you feel fine and your blood counts are normal is, although a good thing, not a reason to continue on a TKI that might be the right on for you.... text book cases? .... the major thing we have learned about TKI therapy over the last decade is that there is no such thing, and that is why in CML we are fortunate enough to have a choice, even though a restricted one.

I think you might have a more clear idea of what to do when you have the results of a mutation test. At least your consultant is willing to be pro-active in trying to get your % of BCR-ABL down to the molecular level. That is a clear goal.

Sandy