Ravulizumab for the Treatment of Generalized Myasthenia Gravis: Timing of Response
Ali Habib1, Michael Benatar2, Tuan Vu3, Andreas Meisel4, Shahram Attarian5, Masahisa Katsuno6, Serena Liao7, Kathleen Beasley7, James Howard8
1University of California, Irvine, 2University of Miami, 3University of South Florida, 4Charité Universitätsmedizin Berlin, 5CHU La Timone Aix Marseille University, 6Nagoya University Graduate School of Medicine, 7Alexion, AstraZeneca Rare Disease, 8The University of North Carolina
Objective:
To assess the timing of first response to ravulizumab in patients with generalized myasthenia gravis (gMG) in the CHAMPION MG study.
Background:
The phase 3 CHAMPION MG study (NCT03920293) demonstrated that ravulizumab is an effective and well-tolerated treatment for anti-acetylcholine receptor antibody-positive (AChR Ab+) gMG. Endpoints for primary data analysis were assessed at Week 26 of the randomized controlled period (RCP); responses at earlier timepoints have not been examined.
Design/Methods:
Data were included from patients with a Myasthenia Gravis-Activities of Daily Living (MG-ADL) total score of ≥6 at ravulizumab initiation who received ravulizumab in the RCP or in the open-label extension. Cumulative MG-ADL response rates at various timepoints after ravulizumab initiation were evaluated. Time to first response (improvement in MG-ADL total score ≥3 points) after ravulizumab initiation was also assessed, using the Kaplan–Meier product-limit method.
Results:
The analysis included 139 patients who were treated with ravulizumab for up to 60 weeks. Cumulative proportions of patients achieving MG-ADL response by Weeks 2, 4, 12, 26, and 60 were 45.3%, 55.4% 66.2%, 75.5%, and 82.0%, respectively. Median (interquartile range) time to first MG-ADL response was 29.0 (170.0) days.
Conclusions:
Cumulative response rates indicate that first response was achieved by almost half of patients after one ravulizumab infusion (by Week 2) and by two-thirds of patients by Week 12; however, some patients (15.8%) achieved a first response after longer treatment. Median time to first response to ravulizumab treatment in patients with AChR Ab+ gMG was approximately 4 weeks.