Metformin for Brain Repair in Children With Cranial-Spinal Radiation for Medulloblastoma

Inclusion Criteria

• •1. Have been treated with cranial or cranial-spinal radiation,
• •2. Are between 5 and 21 years of age at time of consent, and
• •3. Either declare English as their native language or have had at least two years of schooling in English at the time of their baseline assessment.
• •4. Have been diagnosed with a brain tumour requiring treatment with cranial or cranial-spinal radiation at least 2 years ago, is not receiving active treatment and no more than 15 years may have elapsed between treatment with cranial-spinal radiation and time of the trial. Survivors with a shunt will be included in the trial, but will need to be identified prior to study enrollment to discuss any specific considerations for imaging.
• •5. Meet criteria for adequate organ function requirements:
• •1. Adequate renal function defined as: Creatinine clearance or radioisotope glomerular filtration rate (GFR) \> 70ml/min/1.73 m2 or serum creatinine based on age/gender as follows:
• •Maximum Serum Creatinine Level (mg/dL)
• •5 to \< 10 years: Male = 1; Female = 1
• •10 to \< 13 years: Male = 1.2; Female = 1.2
• •13 to \< 16 years: Male = 1.5; Female = 1.4
• •≥ 16 years: Male = 1.7; Female = 1.4
• •2. Adequate liver function defined as:
• •Total bilirubin \< 1.5 x upper limit of normal (ULN) for age, and,
• •serum glutamate oxaloacetate transaminase (SGOT) (AST) or serum glutamate pyruvate transaminase (SGPT) (ALT) \< 3 x upper limit of normal (ULN) for age.
• •6. Females of childbearing potential must have a negative pregnancy test result and must agree to use a medically acceptable method of contraception throughout the entire study period and for 30 days after the last dose of study drug.
• •7. Informed consent will be obtained from the participants and/or their legal guardians by study team members authorized to consent for this study.
• •9. Have a history of congestive heart failure requiring pharmacologic treatment.
• •10. Have a known hypersensitivity to metformin hydrochloride.