Table 2.

Recommended tests for monitoring or investigating CML patients on treatment.

	ROUTINE INVESTIGATIONS ON THERAPY	EXPERIMENTAL/CLINICAL TRIALS
Interphase FISH	• Not recommended May be useful for monitoring response if quality-controlled RT-qPCR not available, including patients with atypical BCR::ABL1 fusions. Cannot be used to define MMR or DMR.	• Not recommended
Qualitative RT-PCR	• Not recommended Very limited value for monitoring response to treatment.	• Not recommended
Cytogenetics	• Suggested at overt hematological relapse, failure according to ELN, or suspected/overt disease progression • Considered in cases in remission but abnormal blood counts Only technique that can detect prognostically-significant ACAs acquired during the course of disease, and chromosome abnormalities in Ph-negative cells.	• Should be considered
Quantitative RT-qPCR or RT-dPCR	• Mandatory for routine molecular monitoring Only technique(s) that can quantify disease levels over full response range specific by ELN and other clinical recommendations, including DMR	• Mandatory
NGS panel for myeloid and lymphoid genes	• Suggested at overt hematological relapse and suspected or overt disease progression May be helpful to confirm progression and occasionally identify potential therapeutic targets	• Recommended Panel analysis during remission useful to determine if variants detected pre-treatment are somatic/germline/clonal hematopoiesis
BCR::ABL1 TKD mutations	• Strongly recommended in cases who fail to reach defined ELN milestones or loss of MMR on TKI therapy Informs subsequent treatment in many cases	• Strongly recommended