Study duration will vary per participant in this event driven trial with a treatment duration of approximately 24 to 48 months.~Participants completing the treatment period will be proposed to enroll in a separate long term safety study.
Primary Objective:~To determine the efficacy of SAR442168 compared to placebo in delaying disability progression in primary progressive multiple sclerosis (PPMS)~Secondary Objectives:~To evaluate efficacy of SAR442168 compared to placebo on clinical endpoints, magnetic resonance imaging (MRI) lesions, cognitive performance, physical function, and quality of life To evaluate safety and tolerability of SAR442168 To evaluate population pharmacokinetics (PK) of SAR442168 in PPMS and its relationship to efficacy and safety To evaluate pharmacodynamics of SAR442168