Steroid Sparing Impact of Ravulizumab in Adults With Generalized Myasthenia Gravis: Post Hoc Analysis From the Phase 3 CHAMPION MG Trial

Topic:

Clinical Trials

Poster Number: 216 M

Author(s):

Katherine Ruzhansky, MD, Medical University of South Carolina, Michael T Pulley, MD, PhD, University of Florida- JAX, Emma Weiskopf, MD, Department of Neurology, Alexion, AstraZeneca Rare Disease, Chloe Sader, PharmD, Department of Neurology, Alexion, AstraZeneca Rare Disease, Svetlana Faktorovich, MD, Marcus Neuroscience Institute

Introduction: For patients with generalized myasthenia gravis (gMG), long-term corticosteroid use is associated with serious adverse effects. Ravulizumab demonstrated clinically meaningful efficacy and safety in the randomized controlled period (RCP) and open-label extension (OLE) period of the phase 3 CHAMPION MG trial (NCT03920293) in adults with gMG. The steroid-sparing impact of ravulizumab was assessed among patients who received concomitant corticosteroids during the OLE period.

Methods: Patients randomized 1:1 received ravulizumab or placebo for 26 weeks (RCP) and then open-label ravulizumab for ≤4 years (OLE). Modification of corticosteroid doses was permitted during the OLE at investigators’ discretion. Changes in Myasthenia Gravis-Activities of Daily Living (MG-ADL) scores and corticosteroid dose changes were assessed and compared between the start of the OLE (OLEbaseline) and the last OLE assessment (OLElast).

Results: In total, 113 of 161 patients who entered the OLE received oral corticosteroids during the OLE (placebo-ravulizumab, n=64; ravulizumab-ravulizumab, n=49). Overall, 60 (53.1%) patients in the OLE decreased or discontinued daily corticosteroids at OLElast vs OLEbaseline (mean dose decrease, 5.8 mg/day). Among these patients, mean MG-ADL scores decreased during the RCP by 2.0 points in the placebo group and by 3.3 points in the ravulizumab group. During the OLE, mean MG-ADL scores decreased by an additional 2.5 points in the placebo-ravulizumab group (P=0.0002) and 1.4 points in the ravulizumab-ravulizumab group (P=0.0087). Overall, mean corticosteroid doses decreased by 12.7 mg/day (62.0%) from OLEbaseline to OLElast (placebo-ravulizumab, −12.3 mg/day [61.7%]; ravulizumab-ravulizumab, −13.3 mg/day [62.4%]). At the OLElast assessment, 51.7% of patients with decreased corticosteroid use were receiving ≤5 mg/day, including 23.3% of patients who had discontinued corticosteroids completely.

Conclusions: Patients who received ravulizumab during the OLE period in CHAMPION MG were able to reduce or discontinue daily corticosteroid use while continuing to show improvement in MG-ADL scores.