Dr. Sarah Hoffmann (Berlin / DE), Dr. Frauke Stascheit (Berlin / DE), Prof. Dr. med. Andreas Meisel (Berlin / DE), Professor Shahram Attarian (Marseille / FR), Professor Jan L. De Bleecker (Gent / BE), Professor John Vissing (Copenhagen / DK), Rene Kerstens (Gent / BE), Edward Brauer (Gent / BE), Kimiaki Utsugisawa (Hanamaki / JP), Neelam Goyal (Stanford, CA / US), Yuebing Li (Cleveland, OH / US), Stojan Peric (Belgrad / RS), Professor James F. Howard Jr (Chapel Hill, NC / US), Francesco Saccà (Neapel / IT)
Abstract-Text (inkl. Referenzen und Bildunterschriften)
Introduction: Treatment with efgartigimod, a human IgG1 antibody Fc-fragment that blocks the neonatal Fc receptor, resulted in clinically meaningful improvements in patients with generalized myasthenia gravis (gMG) in the ADAPT study. Efgartigimod was well tolerated and common adverse events (mostly mild or moderate) were headache, nasopharyngitis, nausea, diarrhea, and upper respiratory/urinary tract infection.
Objective: To assess efgartigimod efficacy in subgroups of patients with gMG.
Methods: Intravenous efgartigimod 10 mg/kg or placebo was administered in cycles of 4 weekly infusions, with subsequent cycles initiated based on clinical evaluation. Efficacy was assessed using Myasthenia Gravis Activities of Daily Living (MG-ADL) and Quantitative Myasthenia Gravis (QMG) scores. Here we report mean change from baseline and responder status (defined as ≥2-point [MG-ADL] and ≥3-point [QMG] improvement for ≥4 consecutive weeks, with first improvement ≤1 week after last infusion) for cycle 1 in anti-acetylcholine receptor autoantibody-positive (AChR-Ab+) patients grouped according to clinical characteristics, including time since diagnosis and concomitant medications.
Results: A greater proportion of efgartigimod-treated patients were MG-ADL responders compared with those receiving placebo regardless of duration of disease (Figure 1A). Likewise, when stratified by concomitant medication use, a greater proportion of efgartigimod-treated patients were MG-ADL responders compared with those taking placebo (Figure 2A). Proportion of QMG responders was similar and consistent across subgroups (Figures 1B and 2B). Mean improvements in MG-ADL/QMG scores were also greater with efgartigimod across all subgroups (Table 1).
Conclusion: The proportion of responders and magnitude of response for patients treated with efgartigimod was consistent regardless of above defined subgroups, providing support for efgartigimod efficacy across a broad population of patients with gMG.