Expert Clinical Perspectives: How should newer therapeutic agents be incorporated into the treatment of patients with myasthenia gravis?
Abstract:
Generalized myasthenia gravis (gMG) is a postsynaptic neuromuscular junction disorder that results in fatigable muscle weakness. The traditional treatment approach includes the use of acetylcholinesterase inhibitors, corticosteroids, and steroid-sparing immunosuppressant therapies (ISTs) for chronic management, whereas exacerbations and crises are managed with intravenous immunoglobulin (IVIg) and plasma exchange (PLEX). Over the past six years, four new therapeutic agents with novel immunological mechanisms of action - complement and neonatal Fc receptor (FcRn) inhibition - were approved as a result of clinically significant improvement in gMG symptoms of those treated with these newer agents in Phase 3 clinical trials. At present, it is unclear when and in whom to initiate these therapeutic agents and how to integrate them into the current treatment paradigm. When selecting a newer therapeutic agent, we use a simple equation: Value = Clinical Improvement/ (Cost + Side Effects + Treatment Burden), which guides our decision making. We consider using these novel therapeutic agents in two specific clinical situations. Firstly, the newer agents are fast-acting, suggesting they can be used in clinically unstable patients as “bridge therapy,” and secondly, they provide additional options for those patients considered treatment-refractory. There are downsides, however, including treatment cost, unique side effect profiles, and intravenous and subcutaneous drug administration (through for some, this may be an advantage). As additional drugs enter the marketplace with unique mechanisms of action, routes of administration and dosing schedules, the placement of the novel therapeutic agents in the gMG treatment algorithm will likely evolve.
The objectives of this activity are to: 1) Be able to determine the clinical situations in which newer therapeutic agents for myasthenia gravis should be considered; 2)Select complement inhibitors and FcRN inhibitors appropriately for treatment of refractory myasthenia gravis. 3)Be able to identify and use complement inhibitors and FcRN inhibitors appropriately as bridge therapy in myasthenia gravis.
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DISCLOSURE INFORMATION
Dr. Zach Simmons (editor) has no conflicts of interest. Relevant financial relationships of the article’s authors have been disclosed and managed through the journal’s editorial review process.
CREDIT DESIGNATION The AANEM is accredited by the American Council for Continuing Medical Education (ACCME) to providing continuing education for physicians. AANEM designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.
Kelly G. Gwathmey MD; Huanghe Ding BS, MPH; Michael Hehir MD; Nicholas Silvestri MD