Multiple plexiform fibromas are a hallmark of type 1 neurofibromatosis, which condition also presents with other findings and symptoms. It can appear as cafe-au-lait spots and bumps under the skin, or it can lead to complications that include blindness, scoliosis and disfigurement. Fibromas can cause pain and compromise other organs. Few treatments are available, although many novel agents are being studied.
The preliminary suggestions of Gleevec’s efficacy in neurofibromatosis have led to two pilot studies. One of the is: Pilot Study of Gleevec/Imatinib Mesylate (STI-571, NSC 716051) in m Neurofibromas (0908-09), NCT01140360Neurofibromatosis (NF1) Patient With Plexifor
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, which are important in the pathogenesis of the disease and experience in 37 NF1 patients treated with Gleevec® in the initial pilot study. Gleevec® will be dosed orally 400 mg/day for adult patients. If tolerated the dose will be increased to 600 mg/day after a minimum of two weeks and will be increased to 800 mg per day after an additional two weeks if tolerated (All escalations minimal at any time). Treatment will continue for 6 months with an option to continue for 24 months if the patient is deriving a clinical benefit.
This followed the Indian University’s report of a successful laboratory tests and a “compassionate use” of the drug that showed dramatic results in a three-year-old girl at Riley Hospital for Children in Indianapolis.
Clearly, the evidence is very preliminary and much more work remains to be done.
Yang F-C et al. NF1 Tumor Suppressor Haploinsufficient Bone Marrow Complements Nullizygous Schwann Cells to Form Plexiform Neurofibromas. Cell, October 31, 2008, Vol. 135, pp. 437-448
Gupta, A., Cohen, B.H., Ruggieri, P., Packer, R.J., Phillips, P.C. Phase I study of thalidomide for the treatment of plexiform neurofibroma in neurofibromatosis 1 Neurology 2003 60: 130-132
V. C. Williams, J. Lucas, M. A. Babcock, D. H. Gutmann, B. Korf, and B. L. Maria Neurofibromatosis Type 1 Revisited Pediatrics, January 1, 2009; 123(1): 124 – 133.