To describe treatment patterns and healthcare resource utilization (HCRU) of patients with newly diagnosed juvenile myasthenia gravis (JMG).

Myasthenia gravis (MG) is a rare, chronic, autoimmune disease characterized by dysfunction and damage at the neuromuscular junction. JMG (MG in patients <18 years old) is very rare, with limited knowledge on current treatment patterns and HCRU.

JMG patients, newly diagnosed between 2008 and 2021, were identified from Merative™ Marketscan® Commercial Database and Multi-State Medicaid Database. Patients were followed from the date of first JMG claim (JMG diagnosis or treatment with acetylcholinesterase inhibitors [AChEIs], maintenance intravenous [IV] or subcutaneous immunoglobulin [Ig], or plasma exchange [PLEX] therapy, whichever occurred first). JMG-related treatment changes during follow-up were assessed by descriptive statistics. Exacerbations, myasthenic crisis, thymectomy, and acute use of IVIg/PLEX during follow-up were identified and HCRU evaluated.

630 newly diagnosed JMG patients (57.6% pre-puberty-onset; <12 years old) were followed for a median of 2.4 years (range 18 days–13 years). Of 533 treated patients, 375 (70.4%) were first treated with AChEIs initiated at a median of 2 days from first JMG claim; corticosteroids were started at a median of 66 days, followed by maintenance Ig/PLEX and non-steroidal immunosuppressants (NSISTs) at 133 and 240 days, respectively. Treatments for post-puberty-onset patients (≥12 years old) were escalated faster than for pre-puberty-onset patients. Thymectomy was most frequent during maintenance Ig/PLEX (29.1 per 100 person-years) and was more frequent in post-puberty-onset patients. Exacerbation peaked during first NSIST treatment (incidence rate 122.9 per 100 person-years); patients treated with maintenance Ig/PLEX had the highest rate of MG hospitalizations (113.9 per 100 person-years).