Table 1.

Critical milestones in first-line CML therapy as defined by the European LeukemiaNet,⁹ the National Comprehensive Cancer Network,¹⁰ and the European Society of Medical Oncology¹¹

Month	Optimal response	Warning	Failure
3 mo
ELN	BCR-ABL1 ≤ 10% ± Ph+ ≤ 35%	BCR-ABL1 > 10% ± Ph+ 36%-95%	No CHR or Ph+ > 95%
NCCN	BCR-ABL1 ≤ 10%	BCR-ABL1 > 10%	NA
ESMO	BCR-ABL1 < 10% ± Ph+ ≤ 35%	BCR-ABL1 > 10% ± Ph+ 36%-95%	No CHR or Ph+ > 95%
6 mo
ELN	BCR-ABL1 < 1% ± Ph+ 0	BCR-ABL1 1%-10% ± Ph+ 1%-35%	BCR-ABL1 > 10% ± Ph+ > 35%
NCCN	BCR-ABL1 ≤ 10%	NA	BCR-ABL1 > 10%
ESMO	BCR-ABL1 < 1% ± Ph+ 0%	BCR-ABL1 1%-10% ± Ph+ 1%-35%	BCR-ABL1 > 10% or Ph+ > 35%
12 mo
ELN	BCR-ABL1 ≤ 0.1%	BCR-ABL1 > 0.1%-1%	BCR-ABL1 > 1% ± Ph+ > 0
NCCN	BCR-ABL1 < 1%	BCR-ABL1 1%-10%	BCR-ABL1 > 10%
ESMO	BCR-ABL1 < 0.1%	BCR-ABL1 0.1%-1%	BCR-ABL1 > 1% ± Ph+ ≥ 1
18 mo
ESMO	BCR-ABL1 < 0.01%	BCR-ABL1 0.1%-1%	NA
At any time >12 mo
ELN	BCR-ABL1 ≤ 0.1%	CCA/Ph− (-7 or 7q-)	Loss of CHR
			Loss of CCyR
			Confirmed loss of MMR*
			Mutations
			CCA/Ph+
NCCN	BCR-ABL1 < 0.1%	BCR-ABL1 0.1%-1%	BCR-ABL1 > 1%
Clinical considerations9,10	Monitor response and side effects	Evaluate for patient compliance and drug interactions	Evaluate for patient compliance and drug interactions
	No change to patient therapy	Consider mutation analysis	Consider mutation analysis
			Recommend TKI switch if no compliance issues or drug interactions identified

All BCR-ABL1 values are expressed using IS. CCA/Ph−, clonal chromosome abnormalities in Ph− cells; CCA/Ph+, clonal chromosome abnormalities in Ph+ cells; CHR, complete hematological response; ELN, European LeukemiaNet; ESMO, European Society of Medical Oncology; NA, not applicable; NCCN, National Comprehensive Cancer Network; Ph+, Philadelphia-positive cells.

^*In 2 consecutive tests, one had BCR-ABL1 transcripts ≥1%.