This study looks at the safety and effectiveness of a medicine called **BRIUMVI® (ublituximab-xiiy)** for people with Relapsing Multiple Sclerosis (RMS). Multiple Sclerosis (MS) is a disease where the immune system attacks the brain and spinal cord. The study wants to understand how people feel when taking this medicine in daily life. To join, you must have MS and not have started BRIUMVI® treatment yet. You cannot join if you had live vaccines like those for chickenpox or measles in the last month, have an active infection, or are in another MS drug study.

• The study checks real-world use of BRIUMVI® for RMS.
• You should not have had your first BRIUMVI® dose before the study.
• You cannot have certain vaccines or infections recently.