Bruton's tyrosine kinase inhibitors in the treatment of multiple sclerosis.

Purpose: In this review, we have highlighted a new class of drugs, Bruton's tyrosine kinase (BTK) inhibitors, and summarized the results of recent clinical trials in the treatment of multiple sclerosis. Views: Multiple sclerosis (MS) is considered an autoimmune disease of the central nervous system, in which B-lymphocytes and myeloid cells, such as macrophages and microglia, play an important role in the pathogenesis. B-cells induce pathological processes by presenting autoantigens to T-lymphocytes, secreting pro-inflammatory cytokines, and forming ectopic lymphoid follicle-shaped clusters. Accordingly, the activation of microglia contributes to the development of chronic inflammation due to the production of chemokines, cytokines, reactive oxygen, and nitrogen species. BTK is an enzyme important in the activation and function of both B-lymphocytes and microglia. The demand for highly effective and well-tolerated drugs still remains at all stages of MS despite the availability of a number of effective drugs against the disease. Thus, in recent years BTK inhibitors have been the newest approach in the treatment of MS, since they affect the leading links of the pathogenesis of this disease and are able to pass through the blood-brain barrier. Conclusions: The study of new mechanisms of the development of MS continues in combination with the elaboration of new treatment methods, i.e., Bruton's tyrosine kinase inhibitors. The review provided the analysis of core studies evaluating the safety and efficacy of these drugs. In the future, positive results of these studies will be able to greatly expand the therapy for various forms of MS.