Biologics and other novel approaches as new therapeutic options in myasthenia gravis: a view to the future.

Myasthenia gravis (MG) is caused by complement-fixing antibodies against the acetylcholine receptors (AChR). Regulatory T cells (T(reg) cells), Th17 cells, and recognition of AChR epitopes by CD4(+) T cells are fundamental. Novel biological agents now in the offing, offer the potential for specific treatment options in MG by targeting the following: (1) T cell intracellular signaling pathways, costimulation, and transduction molecules; (2) B cells, against CD20 molecules, or the B cell trophic factors BAFF and APRIL; (3) complement, against C5 that intercepts the formation of MAC; (4) cytokines and cytokine receptors targeting interleukin (IL)-6, IL-17, and the Janus tyrosine kinases (JAK)1 and JAK3; and (5) cellular adhesion and T cell migration molecules. Reengineering of pathogenic antibodies (i.e., molecular decoys) by constructing recombinant antibodies that block the complement binding of the pathogenic AChR antibodies is an additional approach. The promising therapeutic profile of these agents should be weighted against excessive cost and rare complications necessitating the need for controlled trials to secure efficacy and balance benefit against risks.