Therapeutic Effects of Batoclimab in Chinese Patients with Generalized Myasthenia Gravis: A Double-Blinded, Randomized, Placebo-Controlled Phase II Study

Introduction: We investigated the safety and explore potential efficacy of batoclimab administered subcutaneously in Chinese patients with generalized myasthenia gravis (gMG).

Methods: A randomized, double-blinded, placebo-controlled, parallel phase II study was conducted. First, in the double-blinded treatment period, eligible patients received batoclimab (680 mg), batoclimab (340 mg), or placebo on days 1, 8, 15, 22, 29, and 36. In the open-label treatment period, patients received batoclimab (340 mg) on days 50, 64, and 78. In the follow-up period, patients were examined on days 92, 106, and 120. The primary endpoint was Myasthenia Gravis Activities of Daily Living (MG-ADL) score change on day 43 from baseline.

Results: In total, 30 eligible patients were enrolled, with 11, 10, and 9 patients in the batoclimab 680 mg, batoclimab 340 mg, and placebo groups, respectively. MG-ADL score changes from baseline to day 43 were -2.2 ± 0.9, -4.7 ± 0.6, and -4.4 ± 1.0 in the placebo, batoclimab 340 mg, and 680 mg groups, respectively. Similar changes were observed in Quantitative Myasthenia Gravis, Myasthenia Gravis Composite, and 15-item Myasthenia Gravis Quality of Life scores in the placebo, batoclimab 340 mg, and 680 mg groups, respectively. The proportion of patients with clinically significant improvement on day 43 was higher in the batoclimab groups. On day 120, all four scales in the placebo group had more significant improvement compared with the batoclimab groups, with total serum IgG levels reaching a plateau. No death or treatment-emergent adverse events (TEAEs) led to study discontinuation.

Conclusion: Batoclimab is effective and safe in Chinese patients with gMG.

Trial Registration: This study was registered at ClinicalTrials.gov (NCT04346888) on 15 April 2020, with the first patient enrolled on 23 July 2020.