Selumetinib Drug Found to Shrink Pediatric Neural Tumors

Highlights

• Neurofibromatosis is a genetic disorder which causes tumor in the nervous system.
• Selumetinib drug demonstrates shrinkage of neural tumors in children.
• The drug was found to selectively inhibit MEK protein function.

Selumetinib, a new oral drug was found to demonstrate shrinkage of pediatric neural tumors in children with neurofibromatosis type 1 and plexiform neurofibromas, finds a new study from the National Cancer Institute. The research study was published in the New England Journal of Medicine.

Neurofibromatosis is a genetic disorder which causes abnormal proliferation of cells or results in tumor in the nervous tissue. Neurofibromatosis affects 1 in 3000 people.

Around 50% of the people with neurofibromatosis 1 develop plexiform neurofibromas. Symptoms may cause pain and disability which are diagnosed at an early childhood.

Aim of the Study
The main aim of the study is to evaluate the safety and toxicity of selumetinib drug in patients with neurofibromatosis and plexiform neurofibromas.

Clinical Trial
The phase 1 of the clinical trial study was conducted with 24 patients (11 girls and 13 boys) in September 2011. Selumetinib drug was given twice daily for a period of 30 months. Most of the patients are taking the drug for more than a period of five years.

Findings
The study findings confirmed the inhibition of MEK protein functions in the tumors and the inhibition was diminished within two hours of drug administration.

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The mice were able to demonstrate tumor responses even with regular interruptions. Even limited MEK inhibition were able to cause tumor shrinkage in patients.

Brigitte C. Widemann, M.D., acting chief of the National Cancer Institute's (NCI) Pediatric Oncology Branch, and was sponsored by NCI's Cancer Therapy Evaluation Program, said, "In the future, we may wish to look at intermittent dosing in patients to minimize toxicity and retain maximal outcomes."

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Tumor shrinkage was maintained for approximately 2 years and there were no disease progression in any trial participants.

Dr. Widemann, said, "Some may say that a 20 percent volume reduction is too small to be meaningful, but to me, just stopping the growth of these devastating tumors is an important achievement."

"The difference we see in these patients is truly unprecedented."

In some patients, dose reduction of the drug showed slow regrowth of tumors. Additional studies are required to characterize tumors which does not respond to the drug. Further, clinical trials are carried out to evaluate the efficacy of the drug treatment in children.

Selumetinib Drug

• Selumetinib Drug is a selective inhibitor of MEK protein, which is a part of the complex RAS ( family of related proteins) signaling pathways.
• It is used for the treatment of thyroid cancer, non-small cell lung cancer.
• It is available in the form of a capsule to be taken orally.
• The drug is not yet approved by the Food and Drug Administration in the United States.

Neurofibromatosis

• It is a genetic disorder of the nervous system that is unpredictable.
• More than 100,000 Americans are prone to neurofibromatosis.
• There is no known treatment option to stop the growth of the tumor.
• Complications include abnormal pain, bone deformities, blindness, deafness, cardiovascular disease, psychosocial disabilities and muscle weakness.

References

1. Eva Dombi, M.D. et.al. 'Activity of Selumetinib in Neurofibromatosis Type 1–Related Plexiform Neurofibromas' New England Journal of Medicine; (2016) DOI : 375:2550-2560
2. NEUROFIBROMATOSIS - (http://www.nfnetwork.org/be-an-nf-activist/what-is-advocacy/nf-fact-sheet)
3. Neurofibromatosis - (http://www.brainfacts.org/diseases-disorders/diseases-a-to-z-from-ninds/neurofibromatosis/ )

Source-Medindia