I was diagnosed 3 years ago in Sep 2016 and started on Tasigna 600 mg/day. I reached MMR in 82 days and have been at <.003% (>MR 4.5) or undetected since April of 2017. My last PCR was undetected on June 24th of this year. I experienced multiple side effects early in treatment and worked with my onc to reduce my dose to 450 mg/day on 3/10/17, then to 300 mg/day on 6/15/17 and finally to 150 mg/day on 9/18/17. Virtually all side effects are gone now except for heart arrhythmia. I have had extensive cardio workup including echo and nuclear stress test. Bottom line: I have benign PAC's and PVC's and my cardiovascular system is excellent with no structural problems or blockage of any kind. My cardiologist even said I don't need a cardiologist. I workout 5 -6 days a week, weigh 170 pounds (5' 11") and scored the highest on the stress test that my cardiologist has ever seen for my age group (I am 66).
Nevertheless, I suffer from the arrhythmia on a daily basis - it is uncomfortable and disconcerting even though I know it is benign. I have also read that although uncommon, this could develop into a fib. I have tried beta blockers, calcium channel blockers and am being evaluated next week for sleep disorders that could potentially cause the arrhythmia which I suspect will be negative. There is no way to prove that Tasigna is causing the arrhythmia other than stopping or switching TKI's.
I met with my onc yesterday for a thorough discussion of this issue and I have 4 options:
1. Go off the TKI for a month or so and see if the arrhythmia goes away - if it does, I can switch TKI's, but my onc would require me to start any new TKI at full dose (100 mg Sprycell, 400 mg Bosulif), which I am not willing to do (I know Scuba will say that I should switch oncs, but I am also not willing to do that at this time).
2. Switch TKI's now and see if the arrhythmia goes away, but again I would have to start at full dose which I am not willing to do.
3. Try TFR - I qualify (3 years treatment and 2+ years of sustained DMR) but just barely. The EUROSKI and DESTINY studies showed that TFR success increases between 2 and 8% per year with each year of treatment and each year of sustained DMR, so based on this, my chances at success are meaningfully less than if I waited another 2 - 3 years. My onc said that since my response was deeper and faster than most, my success chances could be higher than someone on treatment longer that took longer to reach DMR. I am not sure this is supported by the data, but that's what he said.
4. Do nothing - stay on 150 mg per day of Tasigna and hope the arrhythmia gets better - it went away one time before for about 4 - 5 months, but has been back consistently on a daily basis since March of this year.
So, I am torn between options 3 and 4 since at least for now 1 and 2 are non-starters for me. I would love to hear what option others on this forum would choose. Thanks.