B-cell therapies tied to fewer early MS relapses, but not less disability

Clinical takeaway: Continue to individualize initial MS treatment based on disease features, safety, monitoring needs, and patient preferences. Consider B-cell–depleting therapy when stronger early control of relapses and MRI activity is a priority, although no disability advantage was evident after two years.

Choosing an initial disease-modifying therapy for multiple sclerosis (MS) requires balancing disease control with safety, monitoring, administration, and patient preference. A two-year cohort study suggests that differences between early treatment strategies may emerge sooner in relapses and MRI findings than in disability.

The study included 509 previously untreated people newly diagnosed with MS, with an average age of 33. Participants were grouped according to the first treatment they started within six months.

People receiving rituximab or ocrelizumab, which reduce B cells, had the fewest relapses—about 4 per 100 patients each year, compared with 16 per 100 among those taking dimethyl fumarate or teriflunomide. After accounting for patient and disease differences, B-cell therapy was associated with a 62% lower relapse rate and a small reduction in MRI lesion volume.

Other high-efficacy therapies were not associated with significantly fewer relapses or less MRI lesion volume than oral therapy.

Patients receiving B-cell therapy were the most likely to continue their initial treatment. At two years, 94% remained on it, compared with 87% receiving other high-efficacy therapies, 72% receiving oral therapies, and 61% receiving injectable therapies.

Despite these differences, disability scores and blood levels of neurofilament light chain, a marker of nerve-cell injury, did not differ between groups. Longer follow-up will be needed to determine whether early differences in inflammatory disease activity eventually translate into less disability.

“These findings may help doctors and people with MS talk about what to expect from early treatment,” said study author Fredrik Piehl, MD, PhD. “No single treatment will be the best choice for everyone, and patient characteristics need to be considered when selecting therapy. Some treatments were linked to fewer attacks and fewer MRI changes, and by following this group for several more years, we will be able to determine whether differences emerge over the longer term.”

Source: American Academy of Neurology. (2026 Sep 9) Neurol Open Access. Early MS treatments differ most in relapses and MRI lesions, not disability