The agency requires additional time to review information regarding the proposed Tysabri (natalizumab) risk management plan for crohn’s disease. Under this revised timeline, the companies anticipate action from FDA on or before January 13, 2008.
Tysabri is approved as a treatment for multiple sclerosis, although its use is restricted due to an increased risk of progressive multifocal leukoencephalopathy, an opportunistic viral infection of the brain that usually leads to death or severe disability. Although the drug has been shown to be beneficial in Crohn’s disease, the risk of infection and concerns over efficacy led to a negative opinion from EU regulatory body, the Committee for Medicinal Products for Human Use, which the companies are appealing.
The disease usually causes diarrhea and crampy abdominal pain, often associated with fever, and at times rectal bleeding. Loss of appetite and weight loss also may occur. Complications include narrowing of the intestine, obstruction, abscesses, and fistulas (abnormal channels connecting the intestine and other organs, including the skin), and malnutrition.