Tysabri (natalizumab) is the only cell adhesion inhibitor featured in this guide. Cell adhesion inhibitors help prevent T cells and B cells from leaving the bloodstream and entering the brain and spinal cord. These white blood cells normally help fight infection. In MS, they can cross the blood-brain barrier, a protective layer around the brain and spinal cord, and cause inflammation that injures myelin and disrupts nerve messages.
Tysabri is a humanized monoclonal antibody. This means it is a lab-made antibody designed so that most of its structure closely matches antibodies produced by the human body. “Humanized” describes the medication’s structure and does not mean that Tysabri is safer or more effective than other DMTs.
Before treatment, the healthcare team evaluates the following:
Tysabri is approved for adults with relapsing forms of MS:
The goal of Tysabri treatment is long-term control of RRMS. It helps reduce relapses and the development of new or enlarging lesions. It does not stop a relapse that has already started or directly relieve current symptoms.
To cross the blood-brain barrier, T cells and B cells use a protein called alpha-4 integrin to attach to blood vessel walls. Tysabri blocks this protein and limits the number of these cells that enter the brain and spinal cord. This helps reduce inflammation, relapses, and new or enlarging lesions seen on MRI.
Tysabri is given by a trained healthcare professional as an infusion every four weeks. Each infusion takes about one hour. Patients are typically monitored during the infusion and afterward for possible side effects and serious reactions.
Because Tysabri can increase the risk of PML, it is available only through the TOUCH® Prescribing Program. Patients, prescribers, pharmacies, and infusion centers must participate in this safety program. Before each infusion, patients are asked about new health problems and symptoms that could affect whether treatment should continue.
In a major clinical trial, Tysabri was compared with a placebo infusion that did not contain active medication. After one year, people receiving Tysabri had about 68% fewer relapses and far fewer new or enlarging lesions on MRI.
After two years, people receiving Tysabri were less likely to experience continued problems with walking, balance, coordination, or use of their arms and legs than those receiving placebo.
It is important to note that Black participants were underrepresented in Tysabri’s clinical trials. However, later research looked specifically at Black or African American participants with early relapsing MS who received Tysabri for up to four years. Researchers found that clinical outcomes, including relapses and disability measures, were generally comparable to those seen in non-Hispanic White participants.
More recent real-world research involving more than 3,200 people with MS, including 632 Black patients, found that relapse rates decreased across racial and ethnic groups, with no significant difference in relapse-free outcomes between Black and White patients.
Black people with MS may experience a more severe disease course than White people, including greater disability and more frequent involvement of the spinal cord and optic nerves in some studies.
At the same time, Black patients have historically been underrepresented in MS research. That can make it difficult to know whether findings from clinical trials reflect the experiences of everyone living with MS.
Tysabri is encouraging in this regard because research has included Black patients in both clinical-trial and real-world settings. The available evidence does not suggest that Tysabri is less effective in Black patients, although more research is needed to understand whether differences in MS itself may affect long-term outcomes.
For Black people living with MS, having treatment research that includes people who look like you matters. It gives patients and their healthcare providers more information to consider when making treatment decisions.
Tysabri can increase the risk of developing progressive multifocal leukoencephalopathy (PML), a rare but serious brain infection caused by the JC virus.
The JC virus (JCV) usually remains inactive in the body and causes no symptoms. In people with reduced immune protection, it can become active and cause PML. JCV antibodies are proteins the immune system makes after exposure to the virus. A positive antibody test shows previous exposure. This does not mean the person has PML; however, it helps the healthcare team estimate PML risk during Tysabri treatment.
Serious risks include:
Contact your healthcare team if you develop:
Seek immediate medical treatment for:
During treatment, the healthcare team continues to check for:
Patients with relapsing multiple sclerosis can find access to Tysabri through several program options. Some of those programs may help lower out-of-pocket medication or infusion costs for eligible patients with private insurance, provide assistance with understanding insurance coverage and financial support options, or help patients locate a TOUCH®-authorized infusion center. Learn more about support and savings for Tysabri.
This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking any drug or commencing or discontinuing any course of treatment.
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