RESPONSE RATES WITH ZILUCOPLAN AMONG GENERALIZED MYASTHENIA GRAVIS PATIENTS IN AN INTERIM ANALYSIS OF RAISE-XT, A PHASE 3 OPEN-LABEL EXTENSION STUDY

Topic:

Clinical Trials

Poster Number: T384

Author(s):

Tuan Vu, MD, University of South Florida, M. Isabel Leite, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK, Renato Mantegazza, MD, Fondazione I.R.C.C.S. Istituto Neurologico Carlo Besta, Babak Boroojerdi, UCB Pharma, Monheim, Germany, Guillemette de la Borderie, UCB Pharma, Brussels, Belgium, Petra W. Duda, MD, PhD, UCB Pharma, Cambridge, MA, USA, Mark Vanderkelen, UCB Pharma, Braine-l'Alleud, Belgium, James Howard, MD, University of North Carolina, Chapel Hill

Introduction:
Zilucoplan, a complement component 5 inhibitor, demonstrated efficacy in a 12-week, Phase 3, randomized, placebo-controlled study (RAISE; NCT04115293) in patients with acetylcholine receptor autoantibody-positive generalized myasthenia gravis (gMG). Long-term data enhances our understanding of the safety and efficacy of zilucoplan in patients with gMG.
Objectives:
To assess responder rates for Myasthenia Gravis Activities of Daily Living (MG ADL) and Quantitative Myasthenia Gravis (QMG) up to 60 weeks of treatment.
Methods:
RAISE-XT (NCT04225871) is an ongoing, Phase 3 open-label extension study, which enrolled adults who completed a qualifying, double-blind study (NCT03315130/NCT04115293). Patients self administered daily subcutaneous injections of zilucoplan 0.3 mg/kg. Primary outcome was incidence of treatment emergent adverse events (TEAEs). Exploratory outcomes included responder rates for MG ADL and QMG (reduction of ≥3 points and ≥5 points without rescue therapy, respectively).
Results:
Out of 200 enrolled patients, 105 continued zilucoplan from their qualifying study, and 95 switched to zilucoplan from placebo (placebo-switch). Median (range) exposure at data cutoff was 1.2 (0.11–4.45) years. TEAEs occurred in 188 (94.0%) patients; 64 (32.0%) patients experienced a serious TEAE. At RAISE-XT baseline (Week 12 of double-blind study), MG-ADL and QMG responder rates were 74.2% and 59.8% for zilucoplan (n=93) and 52.2% and 37.1% for placebo-switch (n=90) groups, respectively. At Week 60, both MG-ADL and QMG responder rates had improved to 87.0% and 84.6% for zilucoplan and 85.7% and 77.1% for placebo-switch groups, respectively.
Conclusions:
In this interim analysis, zilucoplan demonstrated improved MG-ADL and QMG responder rates, sustained up to 60 weeks of treatment, with a favorable safety profile.
Funding: UCB Pharma. These data were previously presented at AANEM, November 1–4, 2023.