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Tysabri® (natalizumab)

Brand Name Chemical Name
Tysabri ®
(formerly called Antegren)
natalizumab (na-ta- lie -zoo-mab)  
Primary Usage in MS Generic Available
Disease-modifying agent No
This medication is given by IV infusion.

The information in this medication sheet has been adapted from the FDA-approved prescribing information for Tysabri.

Description

Tysabri is a laboratory-produced monoclonal antibody. It is designed to hamper movement of potentially damaging immune cells from the bloodstream, across the “blood-brain barrier” into the brain and spinal cord. Tysabri was evaluated in a pair of two-year, controlled clinical trials:

  • Study I compared Tysabri to placebo in patients who had not received any interferon-beta or glatiramer acetate for at least the previous six months.
  • Study II involved patients who had experienced one or more relapses while on treatment with Avonex®. Half of the group took Tysabri in addition to their Avonex; half of the group took Avonex plus a placebo.

In both studies, those taking the medication had a reduced risk of disability progression and experienced fewer exacerbations (relapses) compared with the group taking a placebo. Tysabri has not been studied in people with primary progressive MS or in children.

Approval by the U.S. Food and Drug Administration (FDA)

Tysabri was approved by the U.S. Food and Drug Administration (FDA) in 2006 as a monotherapy (not to be used in combination with another disease-modifying therapy) for the treatment of patients with relapsing forms of MS to delay the accumulation of physical disability and reduce the frequency of clinical exacerbations. Because Tysabri increases the risk of progressive multifocal leukoencephalopathy (PML — see Warnings and Precautions), it is generally recommended for patients who have had an inadequate response to, or cannot tolerate, an alternate MS therapy.

Proper Usage

  • Tysabri is given once every four weeks by intravenous infusion.
  • Because of the risk of PML, Tysabri is available only through a special distribution program called the TOUCH™ Prescribing Program.
    • Before starting treatment with Tysabri, you will learn about the TOUCH program and be asked to sign the Prescriber/Patient Enrollment Form.
    • Only physicians, infusion centers, and pharmacies associated with the infusion centers that are registered with the TOUCH program can prescribe, distribute, or infuse the medication.
  • An MRI scan should be obtained prior to initiating therapy with Tysabri because this MRI may help your physician differentiate multiple sclerosis symptoms that occur over time from symptoms caused by PML.
  • Once you have started taking Tysabri, you should see your prescribing doctor three months after the first infusion, six months after the first infusion, and at least as frequently as every six months thereafter.
  • Before each infusion, you will be asked a series of questions by the doctor or nurse at the infusion center to confirm that Tysabri is still appropriate and safe for you. Tell the doctor or nurse at the infusion center:
    • About all medications you are taking (prescription and non-prescription, including supplements)
    • About any other medical conditions you have
    • If you have experienced any new or worsening medical problems (such as changes in thinking, eyesight, balance, strength, etc.).
    • If you have experienced any hives, itching, or trouble breathing during or after an infusion of Tysabri
    • If you have a fever or infection (including long-lasting infections or shingles)
    • If you are pregnant or plan to become pregnant
    • If you are breastfeeding 

Warnings and Precautions

  • The FDA prescribing information about Tysabri includes a black box warning about the risk of progressive multifocal leukoencephalopathy (PML), a viral infection of the brain that usually leads to death or severe disability.
    • The typical symptoms associated with PML progress over days to weeks, and can include clumsiness and progressive weakness on one side of the body, disturbances of vision, and changes in thinking, memory, and orientation leading to confusion and personality changes. Changes of this kind should be reported immediately to one's physician.
    • There are no interventions that are known to cure PML once it occurs, but a course of plasma exchange to remove Tysabri from the blood stream as quickly as possible may provide some benefit.
    • Although the cases of PML that occurred in the clinical trials occurred only in patients who were also taking another immunomodulating or immunosuppressing medication, additional cases of PML in people who were not taking another immunomodulating or immunosuppressing medication at the same time have been reported in the post-marketing phase.
    • The absolute risk for PML in patients treated with Tysabri cannot be precisely estimated, and the factors that might increase a person's risk of developing PML are not yet known.
    • The relationship between the risk of PML and duration of treatment is not yet known, but most cases of PML were in patients who had been on Tysabri for more than one year.
  • Based on post-marketing experience with Tysabri, the FDA added an additional warning to the product’s labeling information in February, 2008. Tysabri has been found to increase the risk of liver damage, even after a single dose. Any person experiencing symptoms of liver injury, including yellowing of the skin and eyes (jaundice) unusual darkening of the urine, nausea, feeling tired or weak, and vomiting, should contact his or her physician immediately. Blood tests can be done to check for liver damage. Treatment with Tysabri should be discontinued in anyone with jaundice or laboratory findings that indicate significant liver injury.
  • Tysabri can increase the risk for certain infections, including PML; it should not be used by any person who is taking medication(s) that can weaken the immune system, or anyone who has a medical condition that can weaken the immune system, such as HIV infection or AIDS, leukemia or lymphoma, an organ transplant, or others.
  • Allergic reactions can occur — including serious ones. Symptoms of an allergic reaction can include: hives, itching, trouble breathing, chest pain, dizziness, chills, rash, nausea, flushing of skin, low blood pressure. Serious allergic reactions usually happen within 2 hours of the start of the infusion, but can happen any time after. Contact your physician promptly about any of these symptoms.
  • Tysabri should not be used during pregnancy or by any woman who is trying to become pregnant. Women taking Tysabri should use birth control measures at all times. If you want to become pregnant while being treated with Tysabri, discuss the matter with your physician. If you become pregnant while using Tysabri, contact your physician.
  • No data are yet available on the effects of vaccination in patients receiving Tysabri.

Possible Side Effects

  • Side effects that may go away as your body adjusts to the medication and do not require medical attention unless they continue or are bothersome: headache, pain in your arms or legs*, feeling tired*, joint pain, depression*, diarrhea, pain in the stomach area.
  • Because Tysabri affects your immune system, it can increase your chance of getting an unusal or serious infection, such as pneumonia, serious urinary tract infection, gastroenteritis, vaginal infection, tooth infection, and others. Contact your physican promptly about any problems of this kind.

*Some side effects of Tysabri may be confused with symptoms of MS. A person who abruptly experiences any of these changes should consult his or her health professional.

Tysabri is a registered trademark of Elan Pharmaceuticals, Inc.                                  

Avonex is a registered trademark of Biogen Idec.

Betaseron is a registered trademark of Bayer Schering Pharma Aktiengesellschaft.

Rebif is a registered trademark of Ares Trading S.A.

TOUCH is a trademark of Biogen Idec and Elan Pharmaceuticals, Inc.

News about Tysabri

Update on Tysabri and PML: Company Releases Details of Cases and Risks

Oct 29, 2009
According to information released yesterday by Biogen Idec, there have been 24 confirmed cases of PML among people who have used Tysabri after it became available for prescription in July 2006. Some details about the 24 cases are provided.

European Drug Agency to Weigh Risks/Benefits of Tysabri -- cites 23 cases of PML

Oct 23, 2009
Today the EMEA, the European equivalent of the U.S. FDA, released a statement indicating that one of its advisory committees was launching a review of the risks and benefits of Tysabri in light of 23 confirmed cases of PML that it says have occurred since the drug has been on the market.

Case report: Person treated with Tysabri for MS develops brain cancer (primary central nervous system lymphoma)

Oct 15, 2009
A case report of brain cancer (primary central nervous system lymphoma) developing in a person being treated with Tysabri® (natalizumab, Biogen Idec and Elan Pharmaceuticals) has been published. Achim Berthele, MD (Technische Universitate Munchen, Germany) and colleagues report the case in Annals of Neurology (2009:66[3];403 - 406). Based on this single report, it cannot be confirmed that Tysabri caused (or predisposed to) the lymphoma. However, the authors suggest that any development of new or unusual neurological signs or symptoms in a person taking Tysabri should prompt a diagnostic workup for possible complications. Such monitoring is required in people enrolled in the TOUCH risk management program in the U.S.

Update on Tysabri and PML

Sep 18, 2009
According to the FDA, there have been 13 confirmed cases of PML, a viral infection of the brain that usually leads to death or severe disability, among people who have used Tysabri after it became available for prescription in July 2006. The latest post-marketing safety warnings provided by the FDA on Tysabri can be found at this link: http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm107198.htm

Tysabri Update: New Published Papers Explore its Benefits, and New Case of PML Reported

Feb 10, 2009
Two newly published papers explore aspects of how Tysabri® (natalizumab, Biogen Idec, Inc and Elan Pharmaceuticals) impacts relapsing multiple sclerosis.

Study Reports That Plasma Exchange Can Clear Tysabri from Blood; No Evidence Yet That This Can Help Treat PML

Feb 03, 2009
In a small study of 12 people with MS who were taking Tysabri® (natalizumab, Biogen Idec, Inc and Elan Pharmaceuticals), researchers found that plasma exchange (a blood-cleansing process that involves removing and replacing the liquid portion of blood) could rapidly reduce the concentration of Tysabri in the blood.