800.456.2255

TYSABRI clinical trial results:

In a 2-year clinical trial of relapsing MS patients, 627 people were treated with TYSABRI versus 315 with placebo. TYSABRI decreased the number of relapses by 67% compared with placebo (TYSABRI 0.22 vs placebo 0.67).

10 years of results

What is the TYSABRI Observational Program?

In addition to the clinical trial for TYSABRI, it was further studied in the ongoing TYSABRI Observational Program (TOP). We now have the 10-year interim results. 

What was studied?

This analysis studied the long-term safety and efficacy of TYSABRI in 6148 patients with relapsing multiple sclerosis. These patients took 300 mg of TYSABRI every 4 weeks. 

  • These 6148 patients were at different points in their journey, and took TYSABRI for various lengths of time. For example, 3210 people discontinued TYSABRI and the remaining may have not yet reached the end of the 10-year period
  • Patients had 3 or fewer TYSABRI infusions before being enrolled in the study and data were collected from patients at regular doctor visits every 6 months

What are the limitations to the study?

  • This study has limitations and may not be as reliable as a controlled clinical trial. The findings are not included in the full Prescribing Information for TYSABRI
  • Unlike a clinical trial, all observed patients were treated with TYSABRI, so there was no comparison vs placebo
  • Patients participated in countries outside of the United States, so results may not have been the same in the United States

What was discovered?

NO NEW SAFETY CONCERNS WERE IDENTIFIED

Findings were consistent with the previous studies of TYSABRI for up to 10 years of treatment.

  • 13.5% (829 of 6148 patients) experienced at least 1 serious adverse event. The most common were infection and infestations (PML, pneumonia, urinary tract infection, and herpes zoster) with an incidence of 4.1%
  • 4.7% (290 of 6148 patients) had at least 1 serious treatment-related side effect

PEOPLE TAKING TYSABRI HAD AN

reduction in average number of relapses in the first year of the study,* and the reduction remained the same through all 9 years

*Compared to average number of relapses in the year before they started TYSABRI (1.99 vs 0.24).

We also recommend

See more about TYSABRI safety
Get information on financial and insurance support
Find a treatment center near you
Taking TYSABRI

What is TYSABRI?

TYSABRI is a prescription medicine used to treat relapsing forms of multiple sclerosis (MS), to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease. TYSABRI increases the risk of progressive multifocal leukoencephalopathy (PML). When starting and continuing treatment with TYSABRI, it is important to discuss with your doctor whether the expected benefit of TYSABRI is enough to outweigh this risk. 

It is not known if TYSABRI is safe and effective in children under 18 years of age.

IMPORTANT SAFETY INFORMATION

What is the most important information I should know about TYSABRI?

TYSABRI increases your risk of getting a rare brain infection—called progressive multifocal leukoencephalopathy (PML)—that usually leads to death or severe disability.

  • There is no known treatment, prevention, or cure for PML
  • You should not take certain medicines that weaken your immune system at the same time you are taking TYSABRI. Even if you use TYSABRI alone to treat your MS, you can still get PML
  • Your risk of getting PML is higher if you:
    • have been infected by the John Cunningham Virus (JCV). JCV is a common virus that can cause PML in people who have weakened immune systems, such as people taking TYSABRI. Before or while you receive TYSABRI, your doctor may do a blood test to check if you have been infected by JCV
    • have received TYSABRI for a long time, especially for longer than 2 years
    • have received certain medicines that can weaken your immune system before you start receiving TYSABRI
  • Your risk of getting PML is greatest if you have all 3 risk factors listed above. There may be other risk factors that have not yet been identified
  • Patients who are anti-JCV antibody negative are still at risk for the development of PML due to the potential for a new JCV infection or a false negative test result. Therefore, patients with a negative test result should be retested periodically
  • While you receive TYSABRI, and for 6 months after you stop receiving TYSABRI, it is important that you call your doctor right away if you have any new or worsening medical problems (such as problems with your thinking, eyesight, balance, or strength; weakness on 1 side of your body; and using your arms and legs) that have lasted several days. Tell all of your doctors that you are getting treatment with TYSABRI
  • Because of your risk of getting PML while you receive TYSABRI, TYSABRI is available only through a restricted distribution program called the TOUCH® Prescribing Program

Who should not receive TYSABRI?

Do not receive TYSABRI if you have PML or are allergic to natalizumab or any of the ingredients in TYSABRI.

What should I tell my doctor before receiving each dose of TYSABRI?

Before receiving TYSABRI, it is important to tell your doctor:

  • If you have a medical condition that can weaken your immune system, such as HIV infection or AIDS, leukemia or lymphoma, organ transplant, or others, or if you have any new or worsening medical problems that have lasted several days
  • If you are pregnant or plan to become pregnant or if you are breastfeeding or plan to breastfeed. It is not known if TYSABRI can harm your unborn baby or if the TYSABRI that passes into your breast milk can harm your baby
  • About all of the medicines and supplements you take, especially medicines that can weaken your immune system. If you are not sure, ask your doctor

What are the possible side effects of TYSABRI?

TYSABRI can cause serious side effects. If you have any of the symptoms listed below, call your doctor right away:

  • Herpes infections. Increased risk of infection of the brain or the covering of your brain and spinal cord (encephalitis or meningitis) caused by herpes viruses that may lead to death. Symptoms include sudden fever, severe headache, or confusion. Infection of the eye caused by herpes viruses leading to blindness in some patients has occurred. Call your doctor if you have changes in vision, redness, or eye pain
  • Liver damage. Symptoms include yellowing of the skin and eyes (jaundice), unusual darkening of the urine, nausea, feeling tired or weak, or vomiting
  • Allergic reactions (e.g., hives, itching, trouble breathing, chest pain, dizziness, wheezing, chills, rash, nausea, flushing of skin, low blood pressure), including serious allergic reactions (e.g., anaphylaxis). Serious allergic reactions usually happen within 2 hours of the start of the infusion, but they can happen any time after receiving TYSABRI
  • Weakened immune system. TYSABRI may increase your risk of getting an unusual or serious infection
  • Low platelet counts. TYSABRI may cause the number of platelets in your blood to be reduced. Symptoms include easy bruising, small scattered red spots on your skin that are red, pink or purple, heavier menstrual periods than are normal, bleeding from your gums or nose that is new or takes longer than usual to stop, bleeding from a cut that is hard to stop

The most common side effects of TYSABRI are:

  • Headache, urinary tract infection, lung infection, pain in your arms and legs, vaginitis, stomach-area pain, feeling tired, joint pain, depression, diarrhea, rash, nose and throat infections, and nausea. If you experience any side effect that bothers you or does not go away, tell your doctor

These are not all of the possible side effects of TYSABRI. For more information, ask your doctor. To report side effects to FDA, please call 1-800-FDA-1088.

Please see full Prescribing Information, including Boxed Warning and Medication Guide.

This information does not take the place of talking with your doctor about your medical condition or your treatment.