My PCR has been undetectable for almost 2 years now. But today it came back detected at 0.0067. In my head I know it is probably fine, but still I find it hard to see the numbers detected after so long.
I am on 50mg Dasatinib and we were planning to go to 20mg in September. I am not sure if this will change my doctor‘s thinking about that. We meet later today.
Would you still push for a lower dosage? Is this result just noise or potentially concerning? I think I just need some reassurance.
I would not change anything. Any PCR measurement below 0.01% is noise (accuracy/precision of the test). It could very well be a false reading.
However, psychologically "undetected" is not the same as "any number reported". Every time I have my PCR test, I don't want to see a number either even though I know better.
Stay the course and hopefully when you re-test at your normal interval, the "number" will go away. If "undetected", you should still consider dropping to 20 mg. I can't stress this enough (because it is counter intuitive), when it comes to dasatnib, more drug does not equal more response. Dropping to 20 mg may lead to an even better response. Just a thought.
Thank you, Scuba.
My doctor also calmed me down and said this is absolutely normal to see and she is not worried. She is an expert in CML for over 20 years now. She said half her patients at this stage stay undetectable and half wobble at this noise level. There is no change to our plan and she wants to lower the dosage to 40 or 20 at the next visit unless it goes up a lot more.
Sorry Mike for this surprising result - sounds like Scuba and your doc (among others) know what they are talking about and you are in the best hands!
@Scuba, @others who have experience with this! quick follow up - at what point do you think it would be worth lowering the dose of dasatinib in the course of treatment? I tried talking my onc into lowering my dose from 100mg (just diagnosed in April, haven't even done a repeat PCR since my first) due to terrible side effects - joint pain, thrush, to name a few. She wasn't having it. Said I am too early on in this thing to consider that.
Ty! and hopeful Mike that it is, as you said, "just noise"!!!
Olivia
My specialist now starts all new CML chronic phase patients at 50mg dose if they begin with Dasatinib. She feels there is now enough evidence and studies to show 50mg is a reasonable place to start.
Often happens that they test a drug at one dosage level and that is what it gets approved at. This can make some doctors resistant to start at anything else. Maybe some others know of a good study you can try to share and discuss with your doctor.
Olivia,
You were just diagnosed so you need to be very vigilant. If you show signs of myelosuppression, rashes (mouth sores), dose reduction to 70 mg or even better to 50 mg. is warranted. In some cases, depending on severity of the adverse events, dose interruption may be necessary (it was for me).
To help with joint pain, 400 mg magnesium per day (split morning and night) and 2-4 grams of Curcumin will likely help (also split).
Once your FISH goes to zero and/or PCR < 1.0% lowering dasatinib dose further can be considered. To be complete, I was never on 100 mg dasatinib and on 70 mg for only a week. I was put on 20 mg thereafter and saw my PCR fall gradually at first, then plummet. We are all unique and finding the correct dose for each of us is what doctors should focus on.
(Note: starting a low dose of dasatinib first (i.e. 50 or 20 mg) may provide sufficient and even superior response to allow the body to get used to the drug and enhance immune response. Dasatinib is VERY potent when it works)
Thank you Mike, thank you scuba! 100mg is way too much for me. I much prefer these side effects to the ones I experienced on bosutinib (crazy nausea) but would much prefer to be on a lower dose than 100mg. Looking forward to seeing the new doc, a CML specialist at Memorial Sloan Kettering. Will keep you posted! And Mike, please do the same.
