Phase 2 trial in acetylcholine receptor antibody‐positive myasthenia gravis of transition from intravenous to subcutaneous immunoglobulin: The MGSCIg study. (6th March 2023)

• Record Type: Journal Article
• Authors: Pasnoor, Mamatha; Bril, Vera; Levine, Todd; Trivedi, Jaya; Silvestri, Nicholas J.; Phadnis, Milind; Katzberg, Hans D.; Saperstein, David S.; Wolfe, Gil I.; Herbelin, Laura; Higgs, Kiley; Heim, Andrew J.; Statland, Jeffrey M.; Barohn, Richard J.; Dimachkie, Mazen M.
• Is Part Of: European journal of neurology. Volume 30:Number 5(2023)
• Page Start: 1417
• Page End: 1424
• Publication Date: 2023-03-06
• Subjects: efficacy -- intravenous immunoglobulin -- myasthenia gravis -- Quantitative Myasthenia Gravis score -- subcutaneous immunoglobulin; Neurology -- Periodicals; Nervous system -- Diseases -- Periodicals; 616.8
• DOI: 10.1111/ene.15745
• Languages: English
• ISSNs: 1351-5101

Abstract

Abstract: Background and purpose: Data on maintenance therapy with subcutaneous immunoglobulin (SCIg) in myasthenia gravis (MG) are limited. We report on transitioning acetylcholine receptor (AChR) antibody‐positive (Ab+) MG patients on stable intravenous immunoglobulin (IVIg) regimens as part of routine clinical care to SCIg 1:1.2. Methods: This multicenter North American open‐label prospective investigator‐initiated study had two components: the IVIg Stabilization Period (ISP) enrolling patients already on IVIg as part of routine clinical care (Weeks −10 to −1), followed by transition of stable MG subjects to SCIg in the Experimental Treatment Period (ETP; Weeks 0 to 12). We hypothesized that >65% of patients entering the ETP would have a stable Quantitative Myasthenia Gravis (QMG) score from Week 0 to Week 12. Secondary outcome measures included other efficacy measures, safety, tolerability, IgG levels, and treatment satisfaction. Results: We recruited 23 patients in the ISP, and 22 entered the ETP. A total of 12 subjects (54.5%) were female, and 18 (81.8%) were White, with mean age 51.4 ± 17 years. We obtained Week 12 ETP QMG data on 19 of 22; one subject withdrew from ETP owing to clinical deterioration, and two subjects withdrew due to dislike of needles. On primary analysis, 19 of 22 participants (86.4%, 95% confidence interval = 0.72–1.00) were treatment successes using last observation carried forward ( p = 0.018). Secondary efficacy measures supported MG stability. SCIg was safe and well tolerated, and IgG levels were stable. Treatment satisfaction was comparable between ISP and ETP. Conclusions: MG patients on IVIg as part of their routine clinical care remained stable on monthly IVIg dosage, and most maintained similar disease stability on SCIg.