Assessing Compliance With Mercaptopurine Treatment in Younger Patients With Acute Lymphoblastic Leukemia in First Remission

Inclusion Criteria:

* Diagnosis of ALL, in first remission; enrollment on a Children Oncology Group (COG) therapeutic study for ALL is not required
* At the time of enrollment, patient must have completed at least 24 weeks of maintenance chemotherapy, and is scheduled to receive at least 24 more weeks of maintenance chemotherapy
* Receiving continuous oral 6MP during the maintenance phase of therapy for ALL (held only for toxicity or illness), and will be returning to the clinic every 4 weeks for scheduled appointments while enrolled on COG ACCL1033 (between days 1 and 141)
* Has a designated parent or caregiver who is willing to enter into a mutual agreement with the patient to participate in a daily supervised medication administration routine
* Able and willing to use the MEMS® TrackCap™ (e.g., not using a pillbox or prescribed liquid 6MP)
* Parent/caregiver and patient (if 12 years and older) must be willing to use a cellular telephone to receive medication reminders via text messaging during study period
* Patient and parent/caregiver must speak English or Spanish
* 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

Exclusion Criteria:

* Patients with Down syndrome
* Patients who previously participated in or are currently participating in another intervention clinical trial designed to improve adherence