In the 2-year AFFIRM pivotal trial:

83% of patients taking TYSABRI had no sustained disability progression for 12 weeks vs 71% with placebo (primary endpoint: percentage with sustained increase in disability was 17% vs 29%; p<0.001)1,2
View the complete AFFIRM study description.


How do patients take TYSABRI?

TYSABRI is a 1-hour IV infusion administered once every 28 days.1

  • Recommended dose: 300 mg every 28 days
  • Observe patients during the 1-hour IV infusion and for 1 hour after the infusion is complete
  • How supplied: 300 mg in a 15 mL, sterile, single-dose vial
    • Colorless, clear to slightly opalescent solution for dilution prior to IV infusion

Remember: Only orders from infusion centers and certified pharmacies enrolled in and authorized by the TOUCH® Prescribing Program will be processed. Contact Biogen at 1-800-456-2255.

Find an Infusion Center Near Your Patient

How effective is TYSABRI?

In the AFFIRM trial, a 2-year, multicenter, double-blind, placebo-controlled study in 942 patients with relapsing MS, TYSABRI significantly reduced1,2:

  • Disability progressiona
  • Annualized rate of relapse
  • The number of new Gd+ and new or newly enlarging T2-hyperintense lesions

aDefined as an increase of ≥1.0 point on the EDSS from baseline EDSS ≥1.0 that was sustained for 12 weeks, or a ≥1.5-point increase on the EDSS from a baseline EDSS of 0 that was sustained for 12 weeks.1

Gd+=gadolinium-enhancing; EDSS=Expanded Disability Status Scale.

See Results From the AFFIRM Trial

What should I know about the safety and tolerability of TYSABRI?
Please see Important Safety Information for more details. 

Find Out More About the TOUCH Prescribing Program

Are there monitoring requirements for TYSABRI?
  • Healthcare professionals should monitor patients on TYSABRI for any new sign or symptom that may be suggestive of PML.Consider monitoring patients at high risk for PML more frequently
    • Patients should continue to be monitored for any new signs or symptoms that may be suggestive of PML for ~6 months after discontinuation of TYSABRI
  • In TYSABRI-treated patients with PML, immune reconstitution inflammatory syndrome (IRIS) has been reported within days to several weeks after plasma exchange. Monitoring for development of IRIS and appropriate treatment of the associated inflammation should be undertaken1
  • Patients receiving TYSABRI should also be monitored for signs and symptoms of meningitis, encephalitis, acute retinal necrosis (ARN), hepatotoxicity, hypersensitivity reactions, and other infections, as well as JCV granule cell neuronopathy (GCN), that results in symptoms similar to PML and hemolytic anemia1

PML=progressive multifocal leukoencephalopathy; JCV=John Cunningham Virus.

Find Out More About PML Risk

Can patients take TYSABRI while pregnant or breastfeeding?

Before prescribing TYSABRI, ask your patients if they are pregnant or plan to become pregnant. It is not known if TYSABRI can harm fetal development; there are no adequate data on the risk associated with the use of TYSABRI in pregnant women. Natalizumab has been detected in human milk. There are no data on the effects of this exposure on the breastfed infant or the effects of the drug on milk production.

Please see full Prescribing Information

What financial assistance options are available to help patients get started on and pay for TYSABRI?

When cost may be a concern for your patients, Biogen is here to help them start and continue on TYSABRI.

We will work with your patients based on their individual needs. Biogen Support Services offers a variety of different financial and insurance resources, including:

  • Communicating with insurance companies to clarify and confirm coverage, including assistance with the Prior Authorization process and denied claims
  • Insurance counseling that educates uninsured and underinsured patients on government insurance programs
  • Financial assistance options, including:
    • The Biogen Copay Program, which may lower medication cost for eligible patients with commercial insuranceb
    • Other possible financial assistance, where applicable
  • Reimbursement services to provide coverage support in the administration of TYSABRI
  • An Infusion Copay Assistance Program for eligible patients

Help Your Patients Get Support
Your patients can call 1-800-456-2255 Monday-Friday from 8:30 AM to 8 PM ET. Hablamos español.

bEffective January 1, 2021, there is an annual cap on the amount of assistance that patients can receive over a one-year period. Federal and state laws and other factors may prevent or otherwise restrict eligibility. People covered by Medicare, Medicaid, the VA/DoD, or any other federal plans are not eligible to enroll. You are eligible to enroll in the Biogen Copay Program for as long as it is offered and you are treated with a Biogen relapsing MS medication. The Biogen Copay Program is no longer available for TECFIDERA patients in the states of Massachusetts and California.

Download the Access and Reimbursement Guide

What tools are available to help patients learn more?

Biogen, the company behind TYSABRI, has spent more than 20 years developing treatments for people with relapsing MS. For the most information, your patients can visit our patient-friendly website—

Remind your patients that Biogen Support Coordinators are available to assist with any questions or concerns. Patients can call 1-800-456-2255, Monday through Friday from 8:30 AM to 8:00 PM ET

Learn About Services to Support Your Patients on TYSABRI

AFFIRM=NAtalizumab Safety and EFFIcacy in Relapsing-Remitting Multiple Sclerosis.