Study of Irinotecan on a Weekly Schedule in Children

Irinotecan will be given intravenously (into the vein) over 90 minutes for four weeks in a row. This cycle may be repeated in six weeks as long as the cancer is not getting worse and there are no serious side effects. After one cycle patients will be evaluated to decide if the treatments should continue. If the disease is no worse or better additional courses may be given. If treatment continues, evaluations will be done after the second cycle and then every 2 cycles. If patients choose to participate in this study we would request that they remain in the study for one full cycle. During the first cycle of treatment we would like to draw special blood samples to help us learn how much drug is in the blood. These special studies are called pharmacokinetics. On the first day the drug is given, fourteen blood samples will be drawn. Each blood sample will be about 1/2 teaspoon, for a total of about 3 tablespoons. These samples will only be drawn during the first cycle of therapy. The total amount of blood drawn will be less than 5% of the total blood volume, an amount safe even for small children. Examinations and other blood tests will be done twice a week initially, then weekly to look for side effects of the drug. Patients will have an additional one teaspoon of blood drawn at each of these visits.