Observational Study of Tysabri in Early Relapsing-Remitting Multiple Sclerosis in Anti-JC Virus Antibody Negative Participants

Study Summary

The primary objective of the study is to determine which baseline and yearly response factors (clinical and para clinical) predict overall disease-free status at Month 12 and Month 24, and clinical disease-free status in subsequent Months 36 and 48. The secondary objectives are: To identify prognostic factors at Baseline that predict overall disease-free status at Month 12, and to assess if yearly overall disease-free response factors predict overall disease-free status at Month 24; To evaluate clinical disease-free status (relapse, Expanded Disability Status Scale \[EDSS\]) at each analysis time point of Months 12, 24, 36, and 48; To identify prognostic factors at Baseline that predict clinical disease-free status at Month 12, and to assess yearly clinical disease-free response factors that predict clinical disease-free status (relapse, EDSS) in subsequent years at Months 24, 36, and 48; To evaluate the impact of Tysabri at each analysis time point of Months 12, 24, 36, and 48 on the following: annualized relapse rate (ARR), sustained EDSS progression and improvement (24-week sustained); To evaluate the impact of Tysabri at each analysis time point of Months 12, 24, 36, and 48 on the following: magnetic resonance image (MRI) measures: T2, T1, T1 with Gadolinium (Gd), brain atrophy; To evaluate the impact of Tysabri at Month 24 and Month 48 on the following: optical coherence tomography (OCT), Low and High Contrast Visual Acuity Assessment; To evaluate the impact of Tysabri at each analysis time point of Months 12, 24, 36, and 48 on the following: cognitive impairment (Symbol Digit Modalities Test \[SDMT\]), capacity for work (Work Productivity and Activity Impairment Questionnaire \[WPAI\]), quality of life (QoL) (Multiple Sclerosis Impact Scale \[MSIS-29\])

Primary Outcome

Overall disease activity-free is defined as no relapses, no disability progression (RRMS), and absence of MRI disease activity (no gadolinium \[gd\])+ lesions, no new or enlarging T2-hyperintense lesions). A clinical relapse is defined as new or recurrent neurological symptoms, not associated with fever, lasting for at least 24 hours, and followed by a period of 30 days of stability or improvement. Sustained disability progression defined by at least a 1.0-point increase on the EDSS from a Basel

Interventions

• BIOLOGICAL natalizumab