Real-World Utilization Patterns of Intravenous Immunoglobulin in Adults With Generalized Myasthenia Gravis in the United States

Abstract

ObjectiveTo evaluate real-world utilization patterns of intravenous immunoglobulin (IVIg) among patients with generalized myasthenia gravis (gMG) over 3 years post-IVIg initiation.BackgroundgMG is a rare autoimmune neuromuscular disorder with no known cure. Although IVIg is the most commonly used add-on therapy after standard of care treatments in gMG, it is currently unclear whether it is more commonly used as a “one-off” treatment to manage exacerbations, or as maintenance therapy aimed at reducing or replacing steroid use.Design/MethodsPatients with gMG who initiated IVIg treatment were identified from a US claims database (Symphony Health, an ICON plc Company, Integrated Dataverse [IDV]®, January 1, 2014-December 31, 2019). The frequency of subsequent IVIg treatment and associated cost during the first 12 months post-IVIg initiation were analyzed. Usage patterns of concomitant gMG treatments during the year preceding and 3 years post-IVIg initiation were compared.ResultsAmong 1225 patients with gMG who initiated IVIg treatment, 706 patients (57.6%) received 1 to 5 IVIg treatment courses (intermittent IVIg users), and 519 patients (42.4%) received = 6 IVIg treatment courses (chronic IVIg users) within the subsequent year. Mean annual medical cost per patient was nearly 2.5-fold higher for chronic vs intermittent IVIg users ($161,478 vs $64,888, p < 0.001). Usage frequency of other immunotherapy treatments did not decrease over the follow-up period, even for patients who continued annual chronic IVIg for 3 consecutive years post-initiation.ConclusionsNearly half of patients with gMG received chronic and multiple IVIg treatment courses within the first year once initiating IVIg treatment, indicating higher usage than expected. For all IVIg initiators, usage frequency of other immunotherapy treatments did not decrease over 3 years despite IVIg initiation.

Updated consensus statement: Intravenous immunoglobulin in the treatment of neuromuscular disorders report of the AANEM ad hoc committee

“…With respect to neuromuscular disorders, IVIG is United States Food and Drug Administration (FDA)‐approved for the treatment of chronic inflammatory demyelinating polyneuropathy (CIDP), multifocal motor neuropathy (MMN), and dermatomyositis. While controlled studies also support its use in off‐label conditions such as Guillain‐Barré syndrome (GBS) and stiff‐person syndrome, 4 IVIG is increasingly being used to treat other neurologic disorders in the absence of high‐quality evidence or a clear underlying immune‐mediated pathophysiology 1,5,6 . Given the limited supply of IVIG, this has contributed to worldwide shortages, rationing, and increased healthcare costs 5 …”