Contact Biogen

MS ActiveSource® offers highly trained MS ActiveSource® Coordinators to answer your questions about relapsing forms of MS and TYSABRI® (natalizumab), and to offer other services, such as:

  • Information on starting therapy
  • Educational materials and tools
  • Cost and insurance assistance
  • Information about financial assistance options for those who can't pay for their medication

Remember, no question is too big or too small. Call MS ActiveSource® toll free: 1-800-456-2255 Monday to Friday, 8:30 AM to 8 PM ET.

You can also write to us at:

MS ActiveSource®
5000 Davis Drive
PO Box 13919
Research Triangle Park, NC 27709

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TYSABRI® (natalizumab) is a prescription medicine used to treat adults with relapsing forms of Multiple Sclerosis (MS). TYSABRI can slow the worsening of symptoms common in people with MS and can decrease the number of flare-ups (relapses). TYSABRI increases the risk of PML. When starting and continuing treatment with TYSABRI, it is important that you discuss with your doctor whether the expected benefit of TYSABRI is enough to outweigh this risk.

Important Safety Information

Please see Full Prescribing Information (PDF) including Boxed Warning and Patient Medication Guide (PDF).

This information is not intended to replace discussions with your healthcare provider.