A Study to Investigate Long-term Safety and Tolerability of Tolebrutinib in Participants With Multiple Sclerosis.

This is a Phase 3 extension, global, multicenter study to assess the long-term safety and tolerability of tolebrutinib in adult participants (aged ≥18 years) with RMS, PPMS, or NRSPMS who were previously enrolled in the Phase 2b LTS (LTS16004) or 1 of the 4 Phase 3 tolebrutinib pivotal trials (GEMINI 1 \[EFC16033\], GEMINI 2 \[EFC16034\], HERCULES \[EFC16645\], or PERSEUS \[EFC16035\]). SUBSTUDY: ToleDYNAMIC substudy

Inclusion Criteria: \- Participants with RMS, PPMS, or NRSPMS who completed the Phase 2b LTS (LTS16004) or 1 of the 4 Phase 3 pivotal tolebrutinib trials (EFC16033, EFC16034, EFC16645, EFC16035) on IMP. OR \- The Phase 2b LTS (LTS16004) or Phase 3 tolebrutinib pivotal trial participants who temporarily discontinued IMP due to a national emergency and completed the trial visits. ToleDYNAMIC Substudy: Inclusion criteria are those of the main study Exclusion Criteria: * Participants are excluded from the study if any of the following criteria apply: * The participant is at risk for or has a persistent chronic, active (including fever higher than 38°C and clinically unstable), or recurring systemic infection, as judged by the Investigator * For participants initiating OL tolebrutinib in the LTS17043 study: Participants at risk of developing or having reactivation of hepatitis, ie, results at the unblinding visit (RMS) or opt-in visit (PMS) for serological markers for hepatitis B and C viruses indicating acute or chronic infection * Active alcohol use disorder or a history of alcohol or drug abuse within 1 year prior to the opt-in visit * Current alcohol intake equal to or exceeding the following at the opt-in visit: more than 2 drinks per day for men and more than 1 drink per day for women * Abnormal ECG during the opt-in visit considered in the Investigator's judgment to be clinically significant, such as QTcF \>500 msec, in the context of this study. * A bleeding disorder, known platelet dysfunction, abnormal platelet count (\