Current evidence of rituximab in the treatment of multiple sclerosis.

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disorder of the central nervous system. The immunopathology of MS involves both T and B lymphocytes. Rituximab is one of the anti-CD20 monoclonal antibody therapies which deplete B-cells. Although some anti-CD20 therapies have been approved by the Food and Drug Administration for treatment of MS, rituximab is used off-label. Several studies have shown that rituximab has a good efficacy and safety in MS, including certain specific patient conditions such as treatment-naïve patients, treatment-switching patients, and the Asian population. However, there are still questions about the optimal dose and duration of rituximab in MS due to the different dosing regimens used in each study. Moreover, many biosimilars have become available at a lower cost with comparable physicochemical properties, pharmacokinetics, pharmacodynamics, efficacy, safety, and immunogenicity. Thus, rituximab may be considered as a potential therapeutic option for patients without access to standard treatment. This narrative review summarized the evidence of both original and biosimilars of rituximab in MS treatment including pharmacokinetics, pharmacodynamics, clinical efficacy, safety, and dosing regimen.