Oral Corticosteroid and Nonsteroidal Immunosuppressant Therapy Use in Patients with Myasthenia Gravis Receiving Ravulizumab, Eculizumab, or Efgartigimod in the USA

Introduction: Oral corticosteroids (OCSs) and nonsteroidal immunosuppressant therapies (NSISTs) remain widely used for the clinical management of patients with generalized myasthenia gravis (gMG), despite well-documented risks. Newer targeted biologic therapies have demonstrated concomitant immunosuppressant therapy reduction; however, long-term comparative real-world evidence remains limited. This retrospective, observational study compared OCS and NSIST use in patients in the USA receiving one of the following US Food and Drug Administration-approved therapies for gMG treatment: ravulizumab or eculizumab (complement protein C5 inhibitor therapies [C5ITs]) or efgartigimod (neonatal Fc receptor antagonist). Methods: Patients were identified using the IQVIA PharMetrics^® Plus claims database from January 1, 2015 to March 31, 2024. Eligible patients had ≥ 2 MG claims filed ≥ 30 days apart by a nonophthalmologic specialist. Treatment index date was the date of first ravulizumab, eculizumab, or efgartigimod claim. All patients assessed were continuously treated with ravulizumab, eculizumab, or efgartigimod during the 12-month follow-up period. Baseline OCS dose was estimated using claims data 3 months before the index date. Change from baseline in OCS average daily dose (ADD), OCS tapering, and NSIST use were assessed over 3-month intervals during the 12-month post-index follow-up period. Results: After 12 months of continuous treatment, the C5IT cohort experienced a significantly greater mean reduction from baseline in OCS ADD compared to the efgartigimod cohort (C5IT, − 11.2 mg/day; efgartigimod, − 3.6 mg/day; P = 0.034), and fewer patients were taking OCS ADD > 30 mg/day (C5IT, 7.5%; efgartigimod, 22.2%). The percentage of patients with NSIST claims decreased by 28.3% within the first 12 months in the C5IT cohort (baseline, 55.2%; month 12, 39.6%) and remained stable in the efgartigimod cohort (baseline, 48.9%; month 12, 48.9%). Conclusion: These results from US clinical practice suggest greater reductions in OCS and NSIST concomitant therapy for patients treated with ravulizumab or eculizumab compared with efgartigimod.