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Generic Name: Natalizumab
Trade Name: Tysabri™

What does this medication do?

Natalizumab (Tysabri) is an alpha-4 integrin receptor antagonist and works by stopping white blood cells from exiting the blood stream to the intestines and causing inflammation. It has been shown to be effective for both induction and maintenance of remission of Crohn's disease.

Natalizumab was originally used for the treatment of multiple sclerosis (MS) and was FDA approved in 2008 for the treatment of moderate-to-severe Crohn's disease, specifically for patients who have not been helped by or are unable to tolerate treatment with anti-TNF therapy. It is one of the newest developments in biologic therapy.

How effective is this medication?

Tysabri appears to work to improve symptoms in about half (1 out of 2) of patients with Crohn's disease. Of those patients who originally responded to Tysabri, at 15 months about half (1 out of 2) patients are in remission.

How is it given?

Natalizumab is given every four weeks as an intravenous infusion in our Pheresis (Infusion) Unit. In order to receive the infusions, you must be enrolled in the TOUCH program, which is a safety program instituted to monitor you for side effects and symptomatic improvement. You will be closely monitored every 4 weeks as part of this program. After the first 12 weeks of therapy, a decision must be made whether or not to continue treatment with the drug. It will be discontinued if you have not shown symptomatic improvement or have any significant side effects. Additionally, you must taper off corticosteroids by 6 months. Close follow up (every 3-4 months) with your physician is required.

The drug cannot be prescribed in combination with any other immunomodulators (6MP, methotrexate, anti-TNF).

Natalizumab is safe and typically well tolerated, but there are rare potential side effects including:

  1. Progressive multifocal leukoenephalopathy (PML). PML is a very rare, but often fatal, irreversible brain infection that caused Natalizumab to be temporarily taken off of the market in 2005 after three patients developed this specific infection. There is no known treatment for PML. Since being back on the market for multiple sclerosis (MS) and more recently for Crohn's disease, there have been a number of other cases of PML. Based on the currently available data, the risk of PML is approximately 0.1% (1 in 1,000 patients).
  2. Allergic reaction - which can include hives, itching, trouble breathing, chest pain, dizziness, wheezing, chills, rash, nausea, flushing of skin, and low blood pressure. Serious allergic reactions usually occur within 2 hours of the start of the infusion, but can happen any time after receiving Tysabri. Please tell your nurse or doctor immediately if you experience any of these symptoms.
  3. Infection - rare. Usually mild. Please notify your physician if you have any fever, chills, or other symptoms of infection.
  4. Liver damage - rare.
  5. Additional side effects are rare, but may included, fatigue, joint pain, depression, diarrhea, rash, and abdominal pain.

Miscellaneous information

You should not receive live vaccines (ex. measles mumps & rubella, chicken pox, nasal flu, nasal H1N1, varicella) while taking this medication. Inactivated vaccines (ex. tetanus, pneumonia, influenza, and Gardisil®) are safe and recommended. It is a good idea to call your doctor or nurse before receiving any vaccinations.

The drug cannot be given in combination with any other immunomodulators (6MP, methotrexate, anti-TNF). Please let us know if you are told to start any new medications.

In order for us to help monitor you, we require blood tests and an office visit at least every 3-4 months. You will receive a copy of all labs and will be notified if changes are necessary. If you do not hear from us either by telephone or in writing within 2 weeks after your blood is drawn, please call the office at 617-667-2802.