Stopping Tyrosine Kinase Inhibitors in Affecting Treatment-Free Remission in Patients With Chronic Phase Chronic Myeloid Leukemia

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 >= 2consecutive years at the time of enrollment

• Please note: The lab evaluating disease status and molecular response for thisstudy must be College of American Pathology (CAP) and/or Clinical LaboratoryImprovement Amendments (CLIA) certified (United States [US] only), sites inother countries must be certified by their accredited authorities. All labsmust use the International Scale guidelines with a sensitivity of detectionassay =< 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 ofenrollment

• Patient agrees to discontinue TKI therapy

• REGULATORY REQUIREMENTS

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

• 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 orrecognition 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 orabnormalities 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 theirinfants

• Female patients of childbearing potential are not eligible unless a negativepregnancy test result has been obtained