I have a question regarding the response definitions. The 2020 'ELN recommendations for treating chronic myeloid leukemia' mention that: "The definition of the response (milestones) to second-line treatment should be the same as to first-line treatment (table 4)".
As I've learned, this is now more strict than in the previous recommendations of 2013, where the criteria for defining warning or failure states for second-line therapy in case of failure to imatinib, were less strict.
What I cannot find is from what point in time one must count in case of failure/warning to 1st line TKI?
In my case: I had a 'warning' response after 3 months with Imatinib, and a 'failure' response at 4 months. Probably due to low Imatinib through levels (so not totally true 'failure' probably) but switched anyway at 4,5 months to Sprycel/Dasatinib. My question is now: do I count from that moment (4,5 months after first starting TKI's) onwards 3 months to see what my response is at '6 months' according to the above mentioned 'table 4'? [because only then I've been 3 months on Sprycel. But this would then be 7,5 months in actual time]. Or is the 6 months as mentioned in 'table 4' of the ELN recommendations always the 6 months counting from the time of diagnosis/starting of 1st TKI treatment? (in my case only 3 days apart).
I hope my question makes any sense. And I'm sorry if the answer is maybe too obvious, but to me this is not clear at the moment and I can't seem to find any clear answers.
Thanks in advance,
Kind regards, Marilyn