Batoclimab as induction and maintenance therapy in patients with myasthenia gravis: Rationale and study design of a phase 3 clinical trial

Abstract

Introduction Batoclimab, a fully human monoclonal antibody that inhibits the neonatal fragment crystallisable receptor, has shown promising phase 2 clinical trial results in patients with generalised myasthenia gravis (gMG). Methods and analysis In this phase 3, randomised, quadruple-blind, placebo-controlled study, adults with gMG will be randomised 1:1:1 to induction therapy with batoclimab 680 mg, batoclimab 340 mg, or placebo, administered once weekly (QW) for 12 weeks as a subcutaneous injection. The primary endpoint is the change from baseline to week 12 on the Myasthenia Gravis Activities of Daily Living (MG-ADL) score. Batoclimab-treated patients achieving a ≥2-point improvement from baseline on MG-ADL at week 10 or week 12 will be re-randomised to maintenance treatment with batoclimab 340 mg QW, batoclimab 340 mg every other week (Q2W), or placebo for 12 weeks; batoclimab-treated patients with a <2-point improvement at week 10 and week 12 will be switched to placebo for the maintenance period and discontinued thereafter. Placebo-treated patients from the induction period will be re-randomised to batoclimab 340 mg QW or Q2W in the maintenance period. All patients who complete the maintenance period and achieve a ≥2-point improvement from baseline in MG-ADL during ≥1 of the final 2 visits of the induction and/or maintenance periods will continue their current batoclimab dose (or switch to batoclimab 340 mg QW for those on placebo) for a 52-week long-term extension (LTE-1). Patients who complete LTE-1 may enter a second, optional 52-week LTE (LTE-2). Ethics and dissemination This trial is being conducted in accordance with the International Council for Harmonisation Guideline for Good Clinical Practice, the Declaration of Helsinki, and each site's Institutional Review Board/Independent Ethics Committee. All patients must provide written informed consent. Results from this study will be published in peer-reviewed journals and presented at national and global conferences. Trial registration number NCT05403541.