Multiple sclerosis (MS) is a common cause of neurological disability among young and middle-aged people, most often with a relapsing-remitting disease course (RRMS). People with MS (PwMS) may experience a wide range of motor and sensory symptoms affecting activities of daily living and less visible symptoms such as fatigue. Disease-modifying therapies (DMTs) are used to reduce risks of disease worsening, and they vary in efficacy, safety, and tolerability. Studies comparing outcomes with different DMTs in large population-based cohorts are rare. Additionally, in Sweden and at Kaiser Permanente Southern California (KPSC), perceived limitations in the efficacy and tolerability of currently approved MS DMTs have led to increasing off-label use of rituximab (RTX), a B-cell-depleting drug that has been approved for rheumatoid arthritis but has not undergone rigorous testing for use in RRMS.
