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Is Tysabri Right for You?


Updated June 26, 2014

Effectiveness: Basically, Tysabri is twice as effective as the CRAB drugs in reducing relapses – a 68% reduction over two years, as opposed to one-third reduction from the CRABs.

History: Tysabri has had a rocky history. It was approved fairly quickly for use in December 2004, then voluntary pulled from the market by Biogen Idec and Elan in late February 2005, just 3 months after its FDA approval. This was done after it was discovered that two people had developed PML (one fatal, one non-fatal) when using Tysabri in combination with Avonex over a 2-year period (a second PML death was later attributed to Tysabri in someone with Crohn’s disease). In Fall 2005, Tysabri was resubmitted to the FDA for "Priority Status" review. On June 5, 2006, the FDA reapproved Tysabri for use in MS under the condition that all prescribers and infusion centers, as well as patients themselves, be enrolled in the TOUCH Prescribing Program, which involves extensive education of all parties and monitoring of the patients.

Ease of Use: Unlike the CRAB drugs, Tysabri is infused in a doctor’s office or infusion center once a month, so there is no injection at home, no storage considerations and you only have to remember to get to the facility once a month.

  • "Wash Out" Period: Before beginning treatment with Tysabri, patients are required to stop their current MS disease modifying treatments, as well as wait for a certain period after receiving high-dose Solu-Medrol. While the specific amount of time required to wait is determined by individual neurologists, the following rough guidelines are applied: CRAB drugs – wait 2 weeks after last dose; Solu-Medrol – wait one month after last dose; chemotherapy-based treatment – waiting time varies according to dosage, but wait at least 3 months and up to one year.
  • Infusion Process: Tysabri is administered by infusion on a monthly basis in an infusion center or a doctor’s office (must be registered with the TOUCH program). The infusion process takes about 2.5 hours, as you must fill out a questionnaire and talk to a nurse prior to the infusion. The infusion itself then takes one hour and you are required to stay for one hour following the infusion for observation, as most allergic reactions happen within 2 hours of the beginning of the infusion.

Safety: The safety of Tysabri beyond 2 years is unknown.

Pregnancy and Breastfeeding: Tysabri is considered to be in "pregnancy category C," meaning that it caused some harm to fetuses in animal studies but the effect in humans is unknown. Tysabri should not be used by women who are pregnant and should be stopped for some time before trying to conceive (usually one to three months; discuss this with your doctor). Tysabri should not be used by women who are breastfeeding.

Contraindications: Clearly, Tysabri should not be taken by people with PML or who are allergic to Tysabri. Besides that, it should not be taken by patients:

  • With Compromised Immune Systems: This includes people with HIV/AIDS, who have had an organ transplant, or who have a condition like leukemia or lymphoma. You should also tell your doctor if you have a recent history of frequent or recurrent infections.
  • Taking Drugs that Affect the Immune System: Tysabri should not be taken if you are currently taking any drugs that may lower immune function (e.g., azathioprine, chemotherapy, cyclosporine) or immunomodulators, including the interferon-based disease-modifying therapies. (See “wash out” period explanation above.) It is extremely important that your doctor knows exactly what you are taking before you start Tysabri, including all over-the-counter medications and supplements. Do not start taking any medications during your treatment with Tysabri before asking your doctor.

Cost: Tysabri costs about 32,000 dollars a year (check exact prices at DestinationRx.com), plus fees from the infusion center or doctor’s office. According to Elan's site (http://www.elan.com/), "Elan and Biogen Idec are committed to making Tysabri accessible to appropriate patients who may benefit from therapy. To achieve this goal, programs have been developed to assist patients who are uninsured or who require financial assistance. Patients who require financial assistance can receive more information by calling MS ActiveSource at 1-800-456-2255."

For more information: Tysabri is made by Biogen Idec and Elan. For more information, call 1-800-456-2255, or visit the Tysabri website.


Polman CH, O'Connor PW, Havrdova E, Hutchinson M, Kappos L, Miller DH, Phillips JT, Lublin FD, Giovannoni G, Wajgt A, Toal M, Lynn F, Panzara MA, Sandrock AW; AFFIRM Investigators. A randomized, placebo-controlled trial of natalizumab for relapsing multiple sclerosis. N Engl J Med. 2006 Mar 2;354(9):899-910.

Rudick RA, Stuart WH, Calabresi PA, Confavreux C, Galetta SL, Radue EW, Lublin FD, Weinstock-Guttman B, Wynn DR, Lynn F, Panzara MA, Sandrock AW; SENTINEL Investigators. Natalizumab plus interferon beta-1a for relapsing multiple sclerosis. N Engl J Med. 2006 Mar 2;354(9):911-23.

Markus Krumbholz, MD; Hannah Pellkofer, MD; Ralf Gold, MD; Lisa Ann Hoffmann, MD; Reinhard Hohlfeld, MD; Tania Kümpfel, MD. Delayed Allergic Reaction to Natalizumab Associated With Early Formation of Neutralizing Antibodies. Arch Neurol. 2007;64:1331-1333

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