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

Inclusion Criteria

- 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

Exclusion Criteria

- Known T3151 mutation

- Additional clonal chromosomal abnormalities in Philadelphia chromosome (Ph) positive

(+) cells at any time prior to enrollment that include "major route" abnormalities

(second Ph, trisomy 8, isochromosome 17q, trisomy 19), complex karyotype or

abnormalities of 3q26.2

- History of accelerated phase or blast crisis CML

- Female patients who are pregnant

- Lactating females are not eligible unless they have agreed not to breastfeed their

infants

- Female patients of childbearing potential are not eligible unless a negative pregnancy

test result has been obtained