Table 3.

Treatment response milestones according to guidelines by BCR::ABL1 ^IS levels (2, 3)^a.

	Response category	Months after treatment initiation			Any time	Actions
		3	6	12
NCCN	Green (TKI sensitive)	≤10%	≤10%	<1% b	N/A	• Monitor response and AEs • Continue on the same TKI b
	Yellow (possible TKI resistance)	>10%	N/A	>1% to 10%
						• Evaluate compliance and drug interactions • Consider mutational and bone marrow cytogenetic analyses to assess for MCyR at 3 months or CCyR at 12 months • Switch TKI, continue the same TKI (other than imatinib) • Consider evaluation for HCT
						• Evaluate compliance and drug interactions • Consider mutational analyses • Switch TKI and evaluate for HCT
	Red (TKI resistance)	N/A	>10%	>10%
ELN	Optimal	≤10%	<1%	≤0.1%	≤0.1%	• Continue treatment
	Warning	>10%	>1% to 10%	>0.1% to 1%	>0.1% to 1%, loss of ≤0.1% (MMR)	• Carefully consideration for continuation or change, depending on patient characteristics, comorbidities, and tolerance c
	Failure	>10%, if confirmed within 1-3 months	>10%	>1%	>1%, resistance mutations, high-risk additional chromosomal abnormalities	• Change treatment

AE, adverse event; CCyR, complete cytogenetic response; ELN, European LeukemiaNet; HCT, hematopoietic cell transplant; IS, International Scale; MCyR, major cytogenetic response; MMR, major molecular response; N/A, not available; NCCN, National Comprehensive Cancer Network; TKI, tyrosine kinase inhibitor.

^aDefinitions are the same across lines of therapy.

^bIf treatment goal is long-term survival, ≤1% at 12 months is optimal. If treatment goal is treatment-free remission, ≤0.1% at 12 months is optimal. If response is optimal, continue the same TKI. A nonoptimal response per goals requires shared decision-making with the patient.

^cAdditional quantitative polymerase chain reaction testing may be indicated if the kinetics of the response are not clear or if toxicity or intolerance cause dose interruptions or reductions.