Consensus Guidelines for the Treatment of Myasthenia Gravis

Myasthenia gravis (MG) is estimated to affect up to 60 000 Americans and over 700 000 people worldwide, though rates are likely even higher because the disease remains underdiagnosed. The prognosis for patients with MG has improved in recent years, due largely to the increasing use of immunomodulating therapies.

However, despite widespread agreement on the use of many MG treatments, there is still no universal standard of care to help guide clinicians. Because of the heterogeneous nature of the disease, no particular treatment approach is optimal for all patients with MG, and most physicians do not treat it often enough to be familiar with the full range of treatment options. Additionally, the “few successful clinical trials in MG have limited generalizability, and even the best of clinical trials cannot balance the use of different available and accepted treatment modalities in a disease as heterogeneous as MG,” explained Donald B. Sanders, MD, a professor of neurology at Duke University School of Medicine in Durham, North Carolina.

As a result of these factors, few “treatments used for MG have Class I evidence of efficacy, and it is increasingly difficult for physicians to get approval for the use of accepted therapies from payors,” he told Neurology Advisor. Some payors have even challenged the use of plasma exchange – which is universally accepted as an effective and critical component of MG treatment – because a major publication stated that there is insufficient evidence to support or refute its use for MG. Given this combination of circumstances, the “consensus process is specifically suited to provide guidance in such a situation,” Dr Sanders said.

To develop consensus-based MG treatment guidelines intended for clinicians worldwide, a task force appointed by the Myasthenia Gravis Foundation of America – of which Dr Sanders is a co-chair – selected a panel of 15 MG experts to “represent the breadth of knowledge and experience and a wide variety of opinions from MG experts internationally,” according to the paper. The experts first voted and agreed upon preliminary definitions of key concepts, including treatment goals, minimal manifestations, remission, ocular MG, impending and manifest crisis, and refractory MG. The panel then met to identify 7 treatment topics to address and to develop initial guidance statements.

After several rounds of anonymous email voting and modifications based on input from panel members, consensus guidelines were developed for the following areas: symptomatic and immunosuppressive treatment of MG, IV immunoglobulin and plasma exchange, treatment of impending and manifest myasthenic crisis, thymectomy in MG, juvenile MG, MG associated with antibodies to muscle-specific tyrosine kinase (MuSK), and management of MG in pregnancy. Below are summary highlights from each area of the guidelines.