To evaluate safety, efficacy, patient satisfaction and preference after switching from intravenous (IV) complement component 5 (C5) inhibitors to subcutaneous (SC) zilucoplan in adults with acetylcholine receptor autoantibody-positive (AChR Ab+) generalized myasthenia gravis (gMG).

Existing antibody C5 inhibitors for gMG are administered intravenously by healthcare professionals, whereas the peptide C5 inhibitor zilucoplan is intended for self-administration by daily SC injection, which may be preferred by some patients.

MG0017 (NCT05514873) is an ongoing Phase 3b, multicenter, open-label, single-arm study with a 12-week main treatment period, and an optional extension period, of daily SC zilucoplan 0.3 mg/kg, with a target enrollment of 20 patients. Adults with AChR Ab+ gMG were eligible if they had clinically stable disease on an IV C5 inhibitor and were willing to switch to zilucoplan. Primary endpoint was incidence of treatment-emergent adverse events (TEAEs). Secondary endpoints included change from baseline (CFB) in Myasthenia Gravis Activities of Daily Living (MG-ADL) and Quantitative Myasthenia Gravis (QMG) scores at Week 12. Patient-reported outcomes included treatment satisfaction, using the Treatment Satisfaction Questionnaire for Medication (TSQM-9) global satisfaction subscore (scored from 0–100), and preference.

At data cut-off (August 11, 2023), eight participants had received zilucoplan and five had completed the 12-week main treatment period. Four (50.0%) participants reported TEAEs; one TEAE was considered treatment related (injection-site pruritus). No serious TEAEs or study discontinuations were reported. At Week 12, mean (standard deviation) CFB in MG-ADL and QMG scores were −1.80 (3.49) and −3.00 (1.63) respectively, and 26.43 (19.50) for TSQM-9 global satisfaction subscore. All five participants preferred zilucoplan to their previous IV C5 inhibitor.