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.
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
Jun 30, 2009
According to Biogen Idec, a tenth confirmed case of progressive multifocal leukoencephalopathy (PML, a viral infection of the brain that usually leads to death or severe disability) has occurred among people who have used Tysabri® (natalizumab, Biogen Idec and Elan Pharmaceuticals) after it became available for prescription in July 2006. The case, reported by the company on June 26, 2009, occurred in a person in Europe who had been taking Tysabri for 30 months. The reported duration of use among these ten people has ranged from about 12 to 35 months.
Two newly published papers explore aspects of how Tysabri® (natalizumab, Biogen Idec, Inc and Elan Pharmaceuticals) impacts relapsing multiple sclerosis. In addition, a fifth case of PML was reported among people prescribed Tysabri. UPDATE: As of June 26, 2009, 10 cases of PML have been reported since the drug was made commercially available.
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.
Label changes recently approved by the U.S. Food and Drug Administration for the drug Tysabri® (natalizumab, Biogen Idec and Elan Pharmaceuticals) now generally recommend the drug for patients who have had an inadequate response to, or inability to tolerate, a single alternate MS therapy; previous wording had suggested that a patient would generally need to do poorly on more than one alternate therapy. This change should improve its coverage by health plans. The new label change also updates warnings related to the potential risk of developing PML, in light of two new cases that developed in individuals who were using it as a monotherapy.
Read more about the first two cases of PML reported in August 2008 after the drug was made commercially available.