Dear Mr. ##########:

Thank you for your inquiry regarding the biologic product, Tysabri
(Natalizumab). Tysabri is currently not approved for sale in Canada.

Permission from the manufacturer has been received to disclose that a new
drug submission for Tysabri has been filed to Health Canada. The submission
is currently under priority review.

Tysabri is not available through the Special Access Programme (SAP). Access
to Tysabri is currently limited to ongoing clinical trials due to product
availability.

If you'd like additional information concerning ongoing clinical trials,
please contact the manufacturer, Biogen Idec Inc. directly.

Sincerely,

Georgette Roy, B.Sc., MBA
Manager
Biotherapeutics & Quality Regulatory Affairs Division
Biologics & Genetic Therapies Directorate
Health Products & Food Branch
Health Canada