Patients are stratified by age, and separate cohorts from each age group receive 1 of 2 single doses of bis-POM PMEA. The lower dose is given to patients ages 3 months through 17 years; if toxicity is acceptable, the other cohort in this age range receives the higher dose. At this point, accrual of infants < 3 months old may begin at the lower dose, followed by accrual of this age group at the higher dose if toxicity is acceptable. Serum drug concentrations are monitored up to 8 hours post dose.