Mechanistic Studies of Phase III Trial With BAF312 in Secondary Progressive Multiple Sclerosis

This study is complementary to a multi-center, randomized, double-blind,parallel-group,
placebo-controlled, variable treatment duration study comparing the efficacy and safety of
BAF312 to placebo in patients with SPMS (NCT01665144). Investigators will explore both
immunological and neuroprotective mechanisms of BAF312 (siponimod), a novel agent in the
setting of a SPMS clinical trial.

This study is part of a multi-center study, with the University of Michigan serving as the
central site.

Inclusion Criteria:

- Participants enrolled in the multicenter, randomized, double-blind, parallel-group,
placebo-controlled, variable treatment duration study comparing the efficacy and
safety of BAF312 to placebo in patients with Secondary Progressive Multiple Sclerosis
(SPMS) Protocol No. CBAF312A2304 (sponsored by Novartis). Refer to ClinicalTrials.gov
record NCT01665144.

- Subjects enrolled at one of the participating AMS04 study sites located in the United
States.

- Subject must be able to provide written informed consent.

Exclusion Criteria:

- Subjects with severe bleeding disorders, platelet count less than
(<)50,000/microliters (μL), and/or who are currently on full anticoagulant therapy
will be excluded from the optional CSF collections.