Every person is different and may react to TYSABRI differently. Just as there are potential benefits with TYSABRI, there are also potential risks. It is important to talk with your healthcare team about both.
TYSABRI increases your risk of getting a rare brain infection—called progressive multifocal leukoencephalopathy (PML)—that usually leads to death or severe disability.
Today, there are 8 years of available data to help understand the estimated risk of PML while taking TYSABRI. Your doctor can help you understand your risk and make the right treatment decision for you. Read the questions below to find out more.
Approximately 50%-60% of the general public is positive for the John Cunningham (JC) Virus. It's that common, and usually, it is harmless. However, the JC Virus can cause PML in people with weakened immune systems.
PML is a rare brain infection that usually leads to death or severe disability. It is a possible side effect of taking TYSABRI. The estimated risk of developing PML is less than 1%. As of today, there is no treatment, prevention, or cure for PML.
You can only develop PML if you’ve been infected by the JC Virus. It is important to know that testing positive for JC Virus antibodies does not mean that you will get PML. You can continue being treated with TYSABRI even if you are JC Virus positive. It is something you will want to discuss with your doctor and healthcare team, and get their recommendation.
Your risk for PML is higher if you:
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. You can continue being treated with TYSABRI even if you are JC Virus positive.
As long as you are taking TYSABRI, you and your healthcare provider will evaluate your risks and monitor any changes to your health.
Your healthcare provider will periodically retest you for the JC Virus antibodies so you can make the best treatment decision, together.
Based on data from 100,000 US patients over 8 years, it is estimated that there is less than or equal to 0.7% risk to develop PML.
The rate of PML among people who are negative for JC Virus antibodies is 1 in 10,000—or 0.01%—regardless of other risk factors.
However, it is still recommended that you continue to be tested regularly over the course of your TYSABRI treatment. It is still possible, but not common, to have a false negative test result or become JC Virus antibody positive. The reported rate of people with relapsing MS who change from JC Virus antibody negative to positive is 3% to 8% annually.
Biogen offers a free blood test (known as Stratify JCV™ antibody).
With the TOUCH® Prescribing Program, you and your healthcare team monitor your risk over time and decide whether or not TYSABRI remains right for you.
The TOUCH program includes your:
The program is designed for your safety, and is available for as long as you are treated with TYSABRI.
Biogen offers a free blood test (known as Stratify JCV™ antibody).
TYSABRI can cause serious side effects. As with any treatment, being aware of how it may affect you is important. If you have any of the symptoms listed below, call your healthcare professional right away:
In addition to the serious side effects, TYSABRI can cause other side effects as well, including:
If you experience any side effect that bothers you or does not go away, tell your healthcare provider.
Before receiving TYSABRI, it is important to tell your healthcare provider:
You may be treated with TYSABRI for as long as you and your healthcare team decide it is right for you. In the US, more than 40% of people being treated with TYSABRI have been using it for more than 5 years.
*Of the 20,816 patients taking TYSABRI, 12,646 (43.9%) have been treated with TYSABRI for >5 years as of December 2020.