100 Summer Street, 30th Floor, Boston, Massachusetts 02110-2106


Contact the Boston law firm of Thornton Law Firm LLP online or at 1-888-341-1405 for a free consultation.

What is Tysabri?

Tysabri (Natalizumab) is a humanized monoclonal antibody marketed by Elan Corp and Biogen Idec.

Who takes it, and for what condition?

It is considered a last-resort treatment for multiple sclerosis (MS) and has been approved to treat Crohn’s disease.

How does Tysabri work?

Tysabri is believed to inhibit white blood cells from getting into the brain and attacking nerves, which appears to result in fewer of the brain lesions that cause multiple sclerosis symptoms.

Studies have linked Tysabri to severe liver damage, in some cases within just a few days of the first dose of the drug.

It also can cause a fatal brain disorder called progressive multifocal leukoencephalopathy (PML), and may be linked to development of melanoma.

What can you do?

If you or someone you love developed PML, liver damage, or any other condition possibly associated with Tysabri, you have valuable legal rights. Please call our toll-free number (1-888-341-1405) to discuss your case with one of our personal injury lawyers.

Trust our Massachusetts products liability attorneys to help

Contact the Boston law firm of Thornton Law Firm LLP online or at 1-888-341-1405 for a free consultation with a recognized leader in Massachusetts defective drug litigation. You have nothing to risk. We offer a fair and accurate assessment of your case.

Tysabri Quick Reference Guide

Generic name

  • Natalizumab

Date approved

  • November 2004


  • Elan Pharmaceuticals


  • Removed 2/2005

Approved uses

  • Multiple Sclerosis

Off-label uses

  • Crohn’s Disease

Serious side effects

  • PML
  • Death

Contact the Boston law firm of Thornton Law Firm LLP online or at 1-888-341-1405 for a free consultation.

Contact Us

Boston's Top Rated Lawyers Super Lawyers AV Peer Reviewed Rated Preeminent

Thornton Law Firm LLP is located in Boston, Massachusetts and serves clients in and around Boston, Revere, Chelsea, Charlestown, Brighton, Somerville, Allston, Everett, Winthrop, Mattapan, Cambridge, Jamaica Plain, Brookline, Roslindale, Malden, Readville, Newtonville, Newton Center, Arlington, Melrose, West Roxbury, Milton, Newton Highlands, Essex County and Suffolk County.

Attorney Advertising. This website is designed for general information only. The information presented at this site should not be construed to be formal legal advice nor the formation of a lawyer/client relationship.
[ Site Map ] [Video Center ]