Plateau in results: update

Yes, lots of us have switched from imatinib to dasatinib.  Informally, and anecdotally, it SEEMS that many people who hate the side effects from a full dose of imatinib (400) find great relief when they switch to dasatinib.  And vice versa!  It SEEMS that people fall in one camp or the other, but not both.  Anyway, back to facts.  Dasatinib has an excellent track record for response, so I think your son will see a downward trend in his PCR.  100 mg is still the recommended starting dose, although there are studies to show 50 mg is just as effective, but he will be OK on that for awhile, don't worry.  BUT, when he gets a nice response and gets down to 0.1 or lower, then yes, he should promptly be moved to 50 mg.  This is because at least a third of dasatinib users develop pleural effusion and it is thought that the higher the dose, the more likely that will happen.  Now, having said that, pleural effusion can be a non-symptomatic, mild side effect.  People living with long-term minimal residual fluid (and remember, this is in the LINING of the lungs, not IN the lungs), like me, maybe have something to worry about in the future by staying with dasatinib for decades - we don't know - but I have maintained 0.005% IS (at least) for the past several years, and I'm happy to live with the fluid, which doesn't affect me in any way on a daily basis.  All other side effects are so, so, so minimal compared to the misery I endured on imatinib 400 mg (although it worked against the CML.)  I've been at this 12 years btw.  I second the advice to avail yourself of further consultation with the CML experts, but I do think that your son is doing well and will continue to do well.  I hope that in his lifetime there will come a true cure.

Hi, it may be that your son's doctor considers him to be at high risk because of his diagnosis with Thalassemia- minor as well as other factors due to his late diagnosis? This might explain why he/she is keen to change his TKI therapy from IM.

However, from what you have said, your son's PCR results have shown that he has 'responsive disease'. The fact that he has had 3 PCR tests that show a stable response to imatinib (IM) 400mg at 0.2% (<1% BCR/ABL1) should be reassuring.

If you read the link to the article (thanks Roza) Why is it critical to achieve a deep molecular response in chronic myeloid leukemia? by Prof. Susan Branford.  She gives an overview of where current (2020) expert thinking is regarding molecular responses/timelines/goals/DMR/TFR etc. I am sure you will find further reassurance.

• "A recent analysis of the German CML-Study IV confirmed the optimal response time to achieve 1% BCRABL1 at about 12 to 15 months for progression-free survival, with progression being development of accelerated phase, blast crisis or death. The study also investigated when it is necessary to regard lack of MMR as treatment failure, indicating that a switch of therapy is warranted. The landmark time point of 2.5 years to achieve MMR showed the largest difference between those with or without MMR with regard to progression-free survival. A specific time to achieve DMR for progression-free survival was not detected. The updated ELN recommendations now state a change of treatment may be considered if MMR is not reached by 36-48 months."

NCCN and ELNet do have slightly different recommendations with NCCN being slightly less stringent. I am not sure where your son is being treated, but if in the UK or EU then his doctor should be following the ELNet recommendations. 

As mentioned before - also by Roza - you may find it helpful to email the Imperial (Hammersmith) expert CML group and share your concerns. See pinned post at the top of this forum.

BTW, there is at least one other person on here with thalassemia minor (beta) trait plus CML.... see the original thread you started.

Sandy

ssss, I had a reason.for asking you to post your son's test dates and results.

After a CML patient has either been undetected, or plateaued, at levels below 1.0, for a year, or so, it is typically safe to begin gradual dosage reduction.  Your son son may be close to that point.  After. a plateau, CML levels typically drift lower, and do so, regardless of dosage. 

If your son is switched to Sprycel, split the 100mg pills into 50's.  50mg should be the advised dosage.

Buzz

Hi Buzz,

Are you aware of any study or data that supports evidence of a reduction in the IS ratio after a plateau ?

If there is good scientific evidence of this then it be would be helpful in making a decision to accept a switch or not, even if one stayed in a plateau for say up to 24 months after being at a low IS ratio of around 0.2% for 6 or 9 months with no mutation.

Personally I do not really have an appetite for switching from Imatinib unless I really have to as all side effects have settled and I'm just getting on as normal.

Thanks