REPEATED CYCLES OF ROZANOLIXIZUMAB TREATMENT IN PATIENTS WITH MUSCLE-SPECIFIC KINASE AUTOANTIBODY-POSITIVE GENERALIZED MYASTHENIA GRAVIS

Topic:

Clinical Trials

Poster Number: T382

Author(s):

Ali Habib, MD, MDA ALS and Neuromuscular Center, University of California, Irvine, Orange, CA, USA, Sabrina Sacconi, MD, Université Côte d’Azur, Pasteur 2 Hospital, Centre Hospitalier Universitaire de Nice, Nice, France, Robert M. Pascuzzi, Neurology Department, Indiana University School of Medicine, Indianapolis, IN, USA, Marion Boehnlein, UCB Pharma, Monheim, Germany, Bernhard Greve, UCB Pharma, Monheim, Germany, Franz Woltering, UCB Pharma, Monheim, Germany, Vera Bril, BSc, MD, FRCPC, University of Toronto

Introduction
The Phase 3 MycarinG (MG0003/NCT03971422) study demonstrated efficacy of one 6-week cycle of rozanolixizumab in acetylcholine receptor autoantibody-positive and muscle-specific kinase autoantibody-positive (MuSK Ab+) generalized myasthenia gravis (gMG). Patients could then enroll in open-label extensions MG0004 then MG0007, or MG0007 directly.
Objectives
To evaluate the efficacy and safety of rozanolixizumab in patients with MuSK Ab+ gMG over repeated cycles of treatment.
Methods
MG0004 (NCT04124965) evaluated ≤52 weeks of weekly rozanolixizumab infusions. In MG0007 (NCT04650854), after an initial cycle, cycles were administered on symptom worsening (investigator’s discretion). Data were pooled across MycarinG, MG0004 (first 6 weeks) and MG0007 (interim analysis): efficacy pool, patients with ≥2 symptom-driven cycles; safety pool, ≥1 cycle including observation periods across MycarinG (symptom-driven) and MG0007 (fixed/symptom-driven).
Results
127 (12 MuSK Ab+) patients received ≥2 symptom-driven cycles of rozanolixizumab. Slightly greater changes from baseline to Day 43 in mean MG-ADL score were observed in the MuSK Ab+ subgroup, compared to the overall population: Cycle 1, −7.0 (baseline 10.9; n=12) and −3.7 (baseline 8.9; n=127); Cycle 2, −5.7 (baseline 10.8; n=12) and −3.9 (baseline 9.0; n=127); Cycle 3, −4.7 (baseline 10.6; n=7) and −3.4 (baseline 8.9; n=98); Cycle 4, −4.2 (baseline 9.8; n=6) and −3.8 (baseline 8.9; n=75), respectively. Similar patterns were seen in MGC and QMG. 77.8% MuSK Ab+ patients reported ≥1 treatment-emergent adverse event; most were mild to moderate in severity.
Conclusions
Rozanolixizumab efficacy in patients with MuSK Ab+ gMG was maintained over repeated cycles, with an acceptable safety profile, consistent with findings in the overall population.
Funding: UCB Pharma. These data were previously presented at AANEM, November 1–4, 2023.