Pilot Study of Gleevec/Imatinib Mesylate (STI-571, NSC 716051) in Neurofibromatosis (NF1) Patient With Plexiform Neurofibromas

This is a second Pilot Study to determine the efficacy of Gleevec® in neurofibromatosis (NF1) patients with plexiform neurofibromas using new response assessment modalities with the secondary goals of assessing Gleevec toxicity, and characterizing markers of response. The rationale for this study arises from the response of human and murine NF1 cells to Gleevec® in vitro, the response of a NF1 patient treated with Gleevec® for airway compression by a plexiform neurofibroma with a dramatic response not previously seen in NF1 therapy, and the experience in 37 NF1 patients treated with Gleevec® in the initial pilot study. Gleevec will be dosed orally with a starting dose of 100 mg twice daily for patients with a BSA > 1.8 m2 or 55 mg/m2 twice daily for patients with BSA < 1.8 m2. For patients with a BSA > 1.8 m2 the dose will increase by increments of 100 mg bid every two weeks as tolerated up to a maximum dose of 400 mg bid. For patients with a BSA < 1.8 m2 the dose will increase by increments of 55 mg/m2 bid every two weeks as tolerated up to a maximum dose of 220 mg/m2 bid. Treatment will continue for 6 months with an option to continue for 24 months if the patient is deriving a clinical benefit.