Mafosfamide

The purposes of this study are to find the highest dose of mafosfamide that can be given without causing severe side effects, to see how well the combination of these chemotherapy drugs and lower doses of radiation work to delay or stop the growth of the tumor, and to evaluate the pharmacokinetics (how the body handles) of Mafosfamide.

This research study is an investigational treatment with the experimental drug Mafosfamide. This treatment is only for children with cancer that has spread to the meninges (tissues that cover the spinal column and brain) and has continued to grow despite treatment with standard therapy.
Mafosfamide is a drug reported to have antitumor effects in animals and that has been given safely into the cerebrospinal fluid (the fluid within and surrounding the brain) in a small number of children and adults. Since there is limited experience in adults and children in giving mafosfamide in this way, the main purpose of this study is to determine the appropriate safe dose of mafosfamide when given intrathecally, that is directly into the cerebrospinal fluid.
The purposes for this study are to (a) determine what dose of mafosfamide can be safely given into the cerebrospinal fluid through an Ommaya reservoir (surgically implanted catheters used to sample cerebrospinal fluid and to instill medication into the cerebrospinal fluid) and lumbar puncture (spinal tap) or lumbar reservoir; (b) look for side effects of drug treatment; (c) to study the pharmacology (how the human body handles the drug) when given directly into the spinal fluid; and (d) see if this drug is beneficial to the patient.