This study is about testing the long-term safety of a drug called tolebrutinib in adults with different forms of Multiple Sclerosis (MS). MS is a condition where the immune system mistakenly attacks the brain and spinal cord. This study is for people who were already part of earlier trials.

Open-label (OL) means participants know what treatment they are getting. People from earlier studies will either continue or start taking tolebrutinib. If they were taking another drug called teriflunomide, they might need to stop it before starting tolebrutinib.

Participants will take tolebrutinib for about 3 years. To join, they must have been part of previous trials and meet specific health criteria. They can't join if they have certain infections, liver issues, or if they drink too much alcohol.

• Study duration: around 3 years of taking tolebrutinib.
• Participants must have been in previous MS trials.
• Exclusion includes significant health issues like infections or liver disease.

This information is important for deciding if this study is right for you. Always discuss with your doctor before joining any study.