Stopping Tyrosine Kinase Inhibitors (TKI) to Assess Treatment-Free Remission (TFR) in Pediatric Chronic Myeloid Leukemia - Chronic Phase (CML-CP)

• Patient must have been diagnosed with CML-CP at < 18 years of age.

• Patient must have histologic verification of CML-CP at original diagnosis

• Patient must be in molecular remission (MR) with a BCR-ABL1 level of =< 0.01% BCR-ABL1 as measured using the International Scale (IS) by RQ-PCR for >= 2 consecutive years at the time of enrollment

• Please note: The lab evaluating disease status and molecular response for this study must be College of American Pathology (CAP) and/or Clinical Laboratory Improvement Amendments (CLIA) certified (United States [US] only), sites in other countries must be certified by their accredited authorities. All labs must use the International Scale guidelines with a sensitivity of detection assay =< 0.01% BCR-ABL1 and be able to report results in =< 2 weeks

• Patient must have received any TKI for a minimum of 3 consecutive years at time of enrollment

• Patient agrees to discontinue TKI therapy

• REGULATORY REQUIREMENTS

• All patients and/or their parents or legal guardians must sign a written informed consent

• All institutional, Food and Drug Administration (FDA), and National Cancer Institute (NCI) requirements for human studies must be met

• ELIGIBILITY FOR PATIENT-REPORTED OUTCOMES (PROs):

• Age >= 8 years at the time of enrollment

• Ability to understand English or Spanish

• Cognitive ability to complete instruments according to the primary team

• ELIGIBILITY FOR AAML18P1 NEUROCOGNITIVE STUDY:

• Patient must be 5 years or older at the time of enrollment

• English-, French- or Spanish-speaking

• No known history of neurodevelopmental disorder prior to diagnosis of CML (e.g., Down syndrome, Fragile X, William syndrome, mental retardation)

• No significant visual or motor impairment that would prevent computer use or recognition of visual test stimuli