VP.38 A double-blinded, randomized, placebo-controlled phase II study of FcRn antagonist batoclimab in Chinese generalized myasthenia gravis patients

Abstract

A randomized, double-blind, placebo-controlled, parallel phase II study was conducted for generalized myasthenia gravis (gMG) in Chinese population to evaluate the efficacy and safety of batoclimab as a novel anti-FcRn therapy. Eligible patients were randomized in a 1:1:1 ratio to placebo, batoclimab 340 mg, 680 mg groups, respectively. In double-blinded period, patients received batoclimab or placebo on days 1, 8, 15, 22, 29, and 36. In the open-label period, all patients received batoclimab 340 mgon days 50, 64, and 78. In 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. Secondary endpoints included assessment on Quantitative Myasthenia Gravis (QMG), Myasthenia Gravis Composite (MGC), Myasthenia Gravis Quality of Life (MG-QoL), pharmacokinetics, pharmacodynamics and safety events. Totally 30 subjects were randomized, with 9,10 and 11 in the placebo, batoclimab 340mg and 680mg 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 QMG, MGC, and MG-QoL scores. The proportion of patients with clinically significant improvement on day 43 was higher in batoclimab groups. In open-label period, symptom recurrence and IgG levels rise again except the former placebo group. On day 120 the placebo group had more improvement compared to batoclimab groups, with IgG levels reaching a plateau. Treatment-emergent adverse events (TEAEs) were comparable among the three groups. No death or TEAEs leading to study discontinuation was observed. The batoclimab groups experienced mild-to-moderate albumin reductions and total cholesterol elevation, all returned to baseline in follow-up without clinical interference. In conclusion, batoclimab is effective and safe in Chinese patients with gMG.