This study is for slow growing tumors called plexiform neurofibromas (PNF) which are a
relatively common problem in people with neurofibromatosis type 1 (NF1). These tumors are
benign but as they grow, they can become disfiguring as well as disabling or even life
threatening. They often cause pain, difficulty using arms or legs because of spinal cord
compression, and/or nerve damage. At present, the only available therapy for plexiform
neurofibromas is to try to surgically remove as much of the tumor as is possible. Because
these tumors grow into the surrounding areas, total surgical resection is often impossible.
Most tumors will re-grow after surgery if the entire tumor cannot be removed. To date, other
treatments including chemotherapy and radiotherapy have not been able to shrink these tumors.
Interferon is a drug that is used for different types of tumors as well as for hepatitis. It
has been used in the treatment of plexiform neurofibromas (PNF) with some subjects showing
improvement in symptoms and/or a decrease in the size of the tumor. Most subjects had no
further growth of their tumor while on the PEG-Intron. The drug used in this study is PEG
(pegylated)-Intron. PEG-Intron is a long acting form of interferon which keeps the drug from
being broken down in the body for a longer period of time and potentially could be more
effective than the short-acting interferon. PEG-Intron has been approved by the Food and Drug
Administration (FDA) for the treatment of Hepatitis C.
The goals of this study are:
1. To determine how your child's plexiform neurofibroma responds to PEG-Intron when given
weekly.
2. To determine the side effects of PEG-Intron when given weekly to participants with
plexiform neurofibromas.
3. To evaluate a new method of measuring changes in the size of tumors called volume
analysis. This method measures the entire volume of a tumor in three dimensions. The
standard method of measuring tumors uses only the length and/or width of the tumor. By
studying the different ways of measuring tumors the investigators hope to be able to
determine which method is the most accurate and useful.