Long-term Effectiveness and Safety of Eculizumab in Patients With Generalized Myasthenia Gravis (gMG): Real-world Data From Japan
Hiroyuki Murai1, Masanori Mizuno2, Takayuki Kondo3, Mitsuru Watanabe4, Masayuki Masuda5, Masanori Takahashi6, Shigeaki Suzuki7, Masaki Okuda8, Tomoaki Tezuka8, Kimiaki Utsugisawa9
1Department of Neurology, International University of Health and Welfare, 2Department of Neurology, Saiseikai Utsunomiya Hospital, 3Kansai Medical University Medical Center, 4Department of Neurology, Kyushu University, 5Department of Neurology, Tokyo Medical University, 6Department of Clinical Laboratory and Biomedical Sciences, Osaka University Graduate School of Medicine, 7Department of Neurology, Keio University School of Medicine, 8Alexion Pharma GK, 9Department of Neurology, Hanamaki General Hospital
Objective:
To report the third-year analysis from the postmarketing surveillance (PMS) evaluating real-world effectiveness and safety of eculizumab in adults with anti-acetylcholine receptor antibody-positive (AChR-Ab+) gMG.
Background:
Eculizumab was approved in Japan for treatment of gMG in December 2017. Regulatory-mandated PMS of its real-world use is ongoing.
Design/Methods:
This real-world analysis included patients with gMG receiving eculizumab who had eligible data from approval to data cutoff (April 2023). Changes in Myasthenia Gravis Activities of Daily Living (MG-ADL) total score, Quantitative Myasthenia Gravis (QMG), number of crises, intravenous immunoglobulin (IVIg)/plasma exchange (PLEX) use, concomitant oral corticosteroid doses, and safety were assessed.
Results:
The effectiveness analysis included 254 patients (female: 66.1%; mean [SD] age: 53.1 [15.6] years; average [SD] duration of gMG: 7.5 [8.0] years; Myasthenia Gravis Foundation of America [MGFA] classification at first dose: IIa, 20.5%; IIb, 16.9%; IIIa, 21.3%; IIIb, 15.0%; IVa, 7.9%; IVb, 7.1%; and V, 10.2%). Cumulative response rates at 3 years: 179/232 (77.2%) patients had a 2-point change in MG-ADL; 146/224 (65.2%) patients had a 3-point change in QMG. Mean (SD) changes in MG-ADL and QMG scores were ‑5.5 (3.7) and ‑7.7 (5.9), respectively. Mean (SD) changes in MG-ADL scores were ‑4.8 (3.0) and ‑11.7 (4.2) for patients with MGFA class IIa-IVb and MGFA class V, respectively. Similar reductions were seen for QMG. Crises decreased from 20.4/100 patient-years to 2.0/100 patient-years. Proportion of patients receiving IVIg and PLEX decreased from 65.4% to 12.8% and 24.8% to 2.1%, respectively. Concomitant oral corticosteroid use of ≤5 mg/day increased from 11.3% at baseline to 34.2% at cutoff. Among 264 patients in the safety analysis, 40.5% experienced adverse drug reactions (ADRs), and 22.7% had serious ADRs. No meningococcal infections were reported.
Conclusions:
Consistent with previous real-world data, eculizumab treatment demonstrated sustained effectiveness regardless of MGFA classification and was well tolerated. No new safety signals were observed.
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