Today, my wife’s dr indicated that her treatment would be changed from Dasatinib to Nilotinib over concerns she wasn’t responding to Dasatinib, and I’m not certain this is the best course of action. I added as much detail as I could below (apologies for the length).
Please let me know your thoughts, should we look for another opinion before switching treatments?
My wife was started on Dasatinib in late November 2019 - 100mg. After approx 3 weeks, both her neutrophil count and her platelet count were too low to continue treatment and she cycled off. This lasted about 3 weeks before she resumed treatment, but at 70mg.
She was taking the 70mg for 4 days before having to cycle off again due to low neutrophils and we went to see her dr 3 days later. Her blood counts during the visit (4 days after the previous test) were normal and the dr believe the previous test results might have been erroneous. Regardless, my wife’s dose was lowered to 50mg and a PCR test was ordered. Mind you, my wife was only actively on Dasatinib for 25 or so days over the course of 2 months (3 weeks on, 3 weeks off, 4 days on, 3 days off).
Results came in today and showed little to no molecular response. For me, these results were not surprising as she was off Dasatinib more than she was on Dasatinib during the last 2 months, and it had been several weeks since she was on the medication for any meaningful length of time. Also, the literature I’ve read and data I’ve reviewed suggest the indications for MMR/DMR can be observed at 3 months (found one article that looked at 1 month as an indicator, but I haven’t found any supporting articles yet for this correlation study) AFTER being in the medication for the entirety of those 3 months.
Her drs concern is that my wife might not respond to Dasatinib and she is not comfortable with continuing on Dasatinib at 50mg - she would have been ok staying on Dasatinib, but at 100mg (which dropped my wife’s counts and started the cycling). I’ve also read that lower doses of Dasatinib have shown to be as effective as higher doses, but with fewer side effects.
The proposed plan is to switch to Nilotinib at 300mg 2x/day. However, based on my wife’s data, existing literature and my wife’s inconsistent treatment over the last 2 months, I’m concerned the decision to switch is premature and out of an abundance of caution.
I do understand that my wife my react better to Nilotinib and might experience fewer side effects (she has bad headaches in the morning - sorted but some coffee - and fatigue can be an issue, plus the drop in neutrophils and platelets), but quick decisions with minimal / incomplete data are flags for concern for me.