Characterization of Patients Living with Generalized Myasthenia Gravis Initiating Rozanolixizumab in the USA

BACKGROUND: Rozanolixizumab is a neonatal fragment crystallizable receptor blocker approved to treat adults with anti-acetylcholine receptor (AChR) or anti-muscle-specific tyrosine kinase (MuSK) antibody-positive (Ab+) generalized myasthenia gravis (MG) in the USA. OBJECTIVES: This retrospective, observational cohort study aimed to understand the profile of patients initiating rozanolixizumab treatment in the USA. METHODS: Adults with MG who enrolled in a patient support program (ONWARD™) and/or had specialty pharmacy data were included. Descriptive analysis of de-identified data (July 2023-February 2025) was conducted to summarize patient, disease and treatment characteristics, rozanolixizumab use at baseline, and rozanolixizumab use patterns during follow-up. RESULTS: This study included 877 patients, of whom 51.5% were female. Mean (standard deviation [SD]) age was 62.2 (16.6) years; median (range) body weight was 87.0 (36-180) kg. Most patients had MG Foundation of America Clinical Class II or III (38.3% and 46.2%, respectively); 73.1% had anti-AChR Ab+ MG; 15.1% had anti-MuSK Ab+ MG. Baseline mean (SD) MG Activities of Daily Living score (n = 695) was 8.4 (3.8). Most patients (98.3%; n = 578/588) were naïve to rozanolixizumab. The mean (SD) follow-up for patients with ≥ 1 additional treatment date (n = 393) was 33.5 (19.1) weeks. Patients with ≥ 1 year of follow-up since rozanolixizumab initiation (n = 100) started a mean 3.7 cycles in year 1, comparable to the mean 4.1 cycles observed in Phase 3 studies. CONCLUSIONS: In the USA, rozanolixizumab treatment has been initiated in a broad population of patients with MG, with treatment patterns generally consistent with clinical trials.