How TYSABRI Works

How TYSABRI Works: Mechanism of Action

TYSABRI is different and it works differently.

• TYSABRI is an antibody, not an interferon (AVONEX^® (interferon beta-1a), Betaseron^® (interferon beta-1b), Rebif^® (interferon beta-1a))* or glatiramer acetate (Copaxone^®)*
• TYSABRI is thought to inhibit white blood cells from getting into the brain and attacking nerves
• Keeping these cells from attacking nerves is believed to result in fewer brain lesions that cause MS symptoms
• The way in which TYSABRI works has been studied, but the exact way TYSABRI works is not fully known

*AVONEX is a registered trademark of Biogen Idec. All other trademarks are the property of their respective owners.