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Study of Long-term Safety of Tysabri® To Enroll 2500 in North America

Study of Long-term Safety of Tysabri® To Enroll 2500 in North America


Investigators are enrolling 2500 people with relapsing forms of MS at sites in the United States and Canada to study the long-term safety of routine use of Tysabri® (natalizumab, Biogen Idec and Elan Pharmaceuticals). Biogen Idec is sponsoring this study.

For the purposes of this study, “relapsing forms of MS” would include individuals who experience repeated, acute attacks or relapses of symptoms, followed by periods of full or partial recovery.


Tysabri is a laboratory-produced monoclonal antibody. It is designed to hamper movement of potentially damaging immune cells from the bloodstream, across the “blood-brain barrier” into the brain and spinal cord. It showed a high level of therapeutic efficacy during the clinical trials that led to its approval for relapsing forms of MS, but two patients who were taking Tysabri in combination with interferon beta-1a developed PML (progressive multifocal leukoencephalopathy, a rare and frequently fatal disease of the central nervous system). The purpose of this study is to determine the incidence and pattern of serious infections, malignancies, and other serious adverse events in patients with MS treated with Tysabri.

Eligibility and Details:

People with relapsing forms of MS in the United States and Canada who have been receiving Tysabri treatment for three months or less are eligible to participate in TYGRIS. Participants in the United States are required to enroll in the mandatory TOUCH Prescribing Program. In Canada, participants are required to receive Tysabri under routine clinical care.

Participants are receiving standard dosing (300 mg of Tysabri intravenously every four weeks) for five years. Data is being collected by the prescribing physicians during routine clinical visits every six months. Patients will be followed for 5 years regardless of whether or not they continue to take Tysabri.


Participants are being enrolled in the states and provinces listed here. For further information,

United States

Alabama Montana
Arizona North Carolina
California North Dakota
Colorado New Jersey
Washington, DC New Hampshire
Delaware New York
Florida Ohio
Georgia Oklahoma
Iowa Oregon
Idaho Pennsylvania
Illinois Puerto Rico
Indiana Rhode Island
Kansas South Carolina
Kentucky Tennessee
Louisiana Texas
Maine Utah
Massachusetts Virginia
Maryland Washington
Michigan Wisconsin
Minnesota West Virginia
Missourri Wyoming


Manitoba Quebec
Nova Scotia Saskatchewan
Ontario Alberta

Tysabri is a registered trademark of Biogen Idec and Elan.

Stony Brook University Hospital
101 Nicolls Road Stony Brook, NY 11794
(631) 444-4000