must have a confirmed diagnosis of relapsing-remitting multiple sclerosis (rrms) according to mcdonald criteria #1-4 (polman et al, 2005 [appendix i]), and have a prior brain magnetic resonance imaging (mri) demonstrating lesion (s) consistent with multiple sclerosis (ms) from any point in time.

must have an expanded disability status scale (edss) between 0.0 and 5.0, inclusive.

must be taking the same dose of a prescribed ifnβ (either avonex, betaseron, rebif) or ga for at least 12 months consecutively at the time of enrollment and remain on this treatment for the duration of the study. participants receiving rebif must be prescribed 44 μg by subcutaneous injection three times per week.

key exclusion criteria:

primary progressive, secondary progressive, or progressive relapsing ms (as defined by polman et al. 2005).

other chronic disease of the immune system, malignancies, acute urologic, or pulmonary disease.

pregnant or nursing women.

participation within 6 months prior to study enrollment in any other drug, biologic, or device study.

note: other protocol-defined inclusion/exclusion criteria may apply.