Facts About Crohn's Disease
On January 14, 2008, FDA approved Tysabri (natalizumab) for certain patients with moderate-to-severe Crohn's disease. The drug has been approved for patients with evidence of inflammation who have had an inadequate response to, or are unable to tolerate, conventional therapies for Crohn's disease.
These patients must be enrolled in a special restricted distribution program called the Crohn's Disease—Tysabri Outreach Unified Commitment to Health (CD TOUCH) Prescribing Program.
"The addition of Tysabri to the treatment options for sufferers of Crohn's disease is important, but one that carries serious risks," said Daniel Shames, director of the Division of Gastroenterology Products for FDA's Center for Drug Evaluation and Research. Tysabri carries a boxed warning for progressive multifocal leukoencephalopathy (PML), an opportunistic viral infection that affects the brain and can lead to death or severe disability.
Patients treated with Tysabri have also experienced other serious adverse events, including liver injury and anaphylaxis (a life-threatening allergic reaction.) "Health care providers must carefully monitor patients for these risks," Shames said. "The CD-TOUCH Prescribing Program will aid FDA in monitoring this drug through its life cycle."
Tysabri was approved by FDA in June 2006 to treat relapsing forms of multiple sclerosis.
What is Crohn's Disease?
- It is a chronic inflammatory condition of the digestive tract.
- It has been diagnosed in adults and children, and affects about a half million Americans.
- It can occur anywhere in the digestive tract, from the mouth on down. It most commonly affects the lower part of the small intestine.
- It is incurable, but there are treatments available to relieve symptoms.
How Do You Get It?
Medical experts aren't sure. According to the National Institutes of Health, the most popular theory is that the body's immune system reacts abnormally in people with Crohn's disease, mistaking bacteria, foods, and other substances as things that don't belong in the body. The immune system attacks these "invaders," often causing white blood cells to accumulate in the intestinal lining. This causes chronic inflammation that can lead to ulcerations and bowel injury.
What are the Symptoms?
The most common symptoms are abdominal pain—often in the lower right area—and diarrhea. Rectal bleeding, weight loss, arthritis, skin problems, and fever may occur. Bleeding may be serious and persistent, leading to anemia.
How is It Diagnosed?
A thorough physical exam and a series of tests may be required to diagnose Crohn's disease.
What are the Possible Complications?
- A blockage caused by thickening of the intestine is the most common complication of Crohn's disease.
- Sores or ulcers, called "fistulas," that tunnel through the affected area into surrounding tissues. Fistulas often become infected.
- Small tears called fissures may develop in the lining of the mucus membrane of the anus.
- Nutritional effects such as deficiencies of proteins, calories, and vitamins.
- Arthritis, skin problems, inflammation in the eyes or mouth, kidney stones, gallstones, and other diseases of the liver and biliary system.
Research has shown that pregnancy and delivery are usually not impaired in women with Crohn's disease. Still, women with the disease should consult with their doctors before pregnancy.
What are the Treatments?
Available treatments include drugs, nutritional supplements and surgical removal of affected parts of the intestine. Actual treatment depends on the location and severity of disease, complications, and the person's response to previous medical treatments.
Medical therapies include
- anti-inflammation drugs
- cortisone or steroids
- immune system suppressors
- antibiotics
- anti-diarrheal drugs and fluid replacements.
In addition to Tysabri, FDA has approved Remicade (infliximab) and Humira (adalimumab). Both products are approved for the treatment of adults with moderate to severe Crohn's disease that doesn't respond to standard therapies.
In addition, Remicade is approved for the treatment of children 6 years and older, and for the treatment of adult patients with open, draining fistulas. Humira is also approved for the treatment of patients with moderate to severe Crohn's disease who have lost response or are intolerant to Remicade.