My only advice is not to mess around too long with breaks from treatment- unless you have very low levels of disease- i.e MR 4, MR4.5 or MR5.
Dasatinib really is a difficult problem for people who exp. pleural effusion as a side effect, so if it were me I would not wait too long to try an alternative- either nilotinib or one of the other drugs in study.
Re: Ponatinib.
According to data, ponatinib is looking like a really exciting alternative if you can get on the study.
Just to update on how many TKIs there are currently in clinical trial:
Bosutinib (alternative to dasatinib/nilotinib)
Ponatinib (data I have seen looks very good- also deals with T313i and looks like it is effective in Blast and PH+ ALL)
Bafetinib (Abl/Lyn inhibitor- one to watch)
Then there are other alternatives such as:
the synthesized form of Homoharringtonine (a chinese herb) I think this is given intravenously.
Combination of TKi until MMR then maintenance with pegylated interferon to maintain MMR (generally the German study groups)
Reduced Intensity Conditioning (RIC) SCT combining TKi for 12 months post transplant with DLI after that to effect a 'cure'- this is the kind of SCT I had at HH in 2003- I think QE Birmingham are now doing this protocol using nilotinib rather than imatinib)
Whatever choices you have, remember it is essential that as a patient you are fully informed.
I hope you can overcome the PE problem and get on with effective treatment of CML,
best to you both,
Sandy