In the OLE, patients receive intravenous ravulizumab (blind induction or bridging dose for those previously receiving placebo or ravulizumab, respectively, then 3000–3600 mg according to body weight every 8 weeks) for up to 4 years. Assessments include Myasthenia Gravis-Activities of Daily Living (MG-ADL) and Quantitative Myasthenia Gravis (QMG) total scores and safety evaluations.

This interim analysis included data for 79 patients (38 received ravulizumab, 41 received placebo in the RCP) who entered the OLE at least 26 weeks before data cut-off. Improvements in MG-ADL score achieved by ravulizumab-treated patients in the RCP were maintained: least squares (LS) mean change from RCP baseline at Week 52 of -4.2 (95% confidence interval [CI] -5.7, -2.7; p<0.0001). Patients who switched from placebo in the RCP to ravulizumab in the OLE showed rapid improvement in MG-ADL score, which was maintained through 26 weeks (LS mean change from OLE baseline at Week 26 of the OLE: -2.4, 95% CI -3.8, -0.9; p<0.01). Improvements in QMG score were maintained in patients continuing ravulizumab in the OLE and scores improved from OLE baseline in patients switching to ravulizumab. Ravulizumab was well tolerated; no cases of meningococcal infection were reported.

Ravulizumab, administered every 8 weeks, demonstrated sustained improvements in symptoms and was well tolerated for up to 1 year in adults with AChR Ab+ gMG.