JC-Virus (JCV) Antibody Program

JCV Antibody Program in Patients With Relapsing Multiple Sclerosis Receiving or Considering Treatment With Tysabri®: STRATIFY-1

The primary objective is to define the prevalence of serum anti-JCV antibody in relapsing multiple sclerosis (MS) participants receiving Tysabri® (natalizumab) or being considered for such treatment. Secondary objectives are to analytically validate the anti-JCV antibody assay in a plasma matrix and to determine changes in anti-JCV antibody status over time.

This study requires serum, plasma and urine collection at enrollment and every 6 months thereafter for up two years.

Key Inclusion Criteria:

• Relapsing multiple sclerosis (MS) patients interested in or considering beginning treatment with Tysabri® (natalizumab).

Key Exclusion Criteria:

• Patients participating in any other Tysabri® (natalizumab) clinical trial or study sponsored by Biogen Idec or Elan may not participate in this study.

NOTE: Other protocol-defined inclusion/exclusion criteria may apply.