Characteristics, Treatment Patterns, and Disease Burden of Juvenile Myasthenia Gravis in the United States
Jiachen Zhou1, Sigrid Nilius2, Olga Pilipczuk3, Anna Scowcroft4, Thaïs Tarancón5, Frank Tennigkeit2, Piotr Zaremba3, John Brandsema6, Jonathan Strober7
1UCB Pharma, Cambridge, MA, USA, 2UCB Pharma, Monheim, Germany, 3UCB Pharma, Warsaw, Poland, 4UCB Pharma, Slough, UK, 5UCB Pharma, Madrid, Spain, 6Children’s Hospital of Philadelphia, Philadelphia, PA, USA, 7UCSF Benioff Children’s Hospital, San Francisco, CA, USA
Objective:

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

Background:

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.

Design/Methods:

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.

Results:

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).

Conclusions:

JMG patients were escalated rapidly through the treatment hierarchy, but continued to experience exacerbations and high HCRU, suggesting current treatments do not provide adequate disease control. This indicates a need for new, more effective treatment approaches in JMG.

10.1212/WNL.0000000000204878