Targeted biologics in muscle strength restoration and corticosteroid sparing for patients post-myasthenic crisis

Abstract

Myasthenic crisis (MC) represents a life-threatening condition in patients with myasthenia gravis (MG). Despite a substantial reduction in in-hospital mortality for MC, full restoration of muscle strength and quality of life usually requires months or years. It remains unknown whether the sequential use of targeted biologics improves clinical outcomes in patients post-MC compared with the standard of care (SOC). We prospectively followed patients from MC through 6 months post-discharge between November 2018 and November 2025. We then stratified patients into subgroups according to the use of either biologics-based therapy (C5 inhibitors, FcRn antagonists, or rituximab) (BIO) or SOC. The primary endpoint was the Myasthenia Gravis Foundation of America-quantitative MG (MGFA-QMG) score at 6 months after discharge. Secondary outcomes included Myasthenia Gravis Activities of Daily Living (MG-ADL), steroid dose, immunosuppressant (IS) use, cumulative steroid exposure, minimal symptom expression (MSE), and residual symptom burden. At 6 months after discharge, the BIO group ( n = 56) had a lower MGFA-QMG score than the SOC group ( n = 56) (4.51 ± 4.03 vs 6.28 ± 4.72; P = 0.038). Meanwhile, the BIO group required a lower dose of oral corticosteroid (14.74 ± 10.24 vs 21.96 ± 12.87 mg/day; P = 0.004), lower cumulative steroid burden (158.13 ± 64.71 vs 209.24 ± 96.81 mg/day·month; P = 0.001), and had a lower proportion of IS use (47.3% vs 67.9%; P = 0.028). MSE was achieved in 56.86% in the BIO and 60.38% in the SOC group, respectively. Targeted biologics were associated with better objective muscle strength and reduced corticosteroid and IS use after MC, although no significant between-group difference was observed in MG-ADL. A substantial proportion of patients in both groups continued to have residual symptoms at 6 months.