This study compares two ways of giving a medicine called Frexalimab to adults with Multiple Sclerosis (MS). MS is a disease where the body's defense system attacks the brain and spinal cord by mistake. Frexalimab can be given either under the skin (subcutaneous or SC) or into a vein (intravenous or IV). People aged 18 to 60 who have certain types of MS are invited to join. The study lasts for 48 weeks (about a year) and may continue longer for optional safety checks.

• The study requires 11 to 17 visits depending on the method of administration.
• Participants must not have other health issues that could confuse the study results.
• Both men and women should follow certain rules about preventing pregnancy during the study.

Consider joining if you have Relapsing MS (RMS) or non-relapsing Secondary Progressive MS (nrSPMS) and meet the study rules. There will be health checks to see if you qualify, and safety is a priority throughout the study.