The Impact of Efgartigimod on Utilization of Therapeutic Plasma Exchange Procedures for Myasthenia Gravis in One Tertiary Medical Center

Myasthenia gravis (MG) is an autoimmune disorder caused by autoantibodies against proteins of the neuromuscular junction, such as the acetylcholine receptor (AChR). While therapeutic plasma exchange (TPE) has been a standard chronic therapy for patients with poorly controlled MG, new medications have recently been approved by the FDA for such patients. We report the impact of a new therapy, efgartigimod, on the number of therapeutic plasma exchanges performed on patients with generalized MG in our apheresis unit. A retrospective chart review was performed for patients with MG between 2018-2019 (pre-efgartigimod) and 2022-2023 (post-efgartigimod). We evaluated any changes between the two periods, including the total number of MG patients, the proportion of TPEs that were performed for MG, and the proportion of inpatient TPEs for MG. A statistically significant reduction (p < 0.0001) was observed in the proportion of total TPE procedures for MG between the two time periods. In AChR-antibody positive (AChR-Ab +) patients who received both inpatient and outpatient procedures, there was a significant increase in the proportion of inpatient procedures post-efgartigimod (p = 0.0035). Our study demonstrated a decrease in the overall use of chronic TPE for MG over the 2-year period following the release of efgartigimod. However, there will remain a role for TPE in the setting of acute MG flares, the inpatient setting, during pregnancy, and in those who do not tolerate the new medications.