Humoral-targeted immunotherapies in multiple sclerosis.

The continuous improvements of our understanding of the pathophysiological changes that occur in multiple sclerosis (MS) have translated into many novel therapeutic agents at different stages of development. These agents target more specifically the innate or the adaptive immune response. We will review agents available or under development that target the humoral pathways of the adaptive immune response. As such, humoral targeted immunotherapies that are being developed for MS are discussed herein: rituximab, ocrelizumab, and ofatumumab show promise as B-cell depleting agents. Other agents, such as atacicept were suspended during development in MS due to increased inflammatory activity versus the placebo. Although most agents were tested in relapsing-remitting forms of MS, rituximab and ocrelizumab have both been studied in progressive MS, whereas ocrelizumab only is currently moving forward in primary progressive MS trials. We provide an overview of agents available and under development that target the humoral response and include their mechanisms of action, safety profiles, and results of clinical trials.