Real-world safety and effectiveness of mepolizumab for patients with eosinophilic granulomatosis with polyangiitis (EGPA) in Japan: 48-week interim analysis of the MARS study

Tomonori Ishii; Hideaki Kunishige; Tamami Kobayashi; Etsuko Hayashi; Masaki Komatsubara; Takeo Ishii; Rafael Alfonso-Cristancho; Jun Tamaoki; Peter Howarth

doi:10.1093/mr/road109

Real-world safety and effectiveness of mepolizumab for patients with eosinophilic granulomatosis with polyangiitis (EGPA) in Japan: 48-week interim analysis of the MARS study

Mod Rheumatol. 2023 Dec 8:road109. doi: 10.1093/mr/road109. Online ahead of print.

Authors

Tomonori Ishii¹, Hideaki Kunishige², Tamami Kobayashi³, Etsuko Hayashi⁴, Masaki Komatsubara⁴, Takeo Ishii², Rafael Alfonso-Cristancho⁵, Jun Tamaoki⁴, Peter Howarth⁶

Affiliations

¹ Tohoku University Hospital, Clinical Research, Innovation and Education Center, Sendai, Japan.
² Value Evidence & Outcomes, GSK, Tokyo, Japan.
³ Clinical Statistics, GSK, Tokyo Japan.
⁴ Respiratory Medical & Development, GSK, Tokyo, Japan.
⁵ Value Evidence & Outcomes, GSK, Collegeville, PA, USA.
⁶ Global Medical Affairs, GSK, London, UK.

PMID: 38100679
DOI: 10.1093/mr/road109

Abstract

Objectives: : Assess real-world, long-term safety/effectiveness of mepolizumab for eosinophilic granulomatosis with polyangiitis (EGPA) in Japan.

Methods: : MARS (GSK ID:213684/NCT04551989) is an ongoing 96-week study of patients with EGPA who received 4-weekly mepolizumab 300 mg subcutaneously for ≥96 weeks before study entry (baseline) and continued treatment. This interim analysis included safety from baseline to Week 48 (observation period) and clinical outcomes before mepolizumab and during the observation period.

Results: : Of 118 patients enrolled, 29% (34/118) experienced adverse events (AEs) of which 13% (15/118) experienced serious AEs; none were considered mepolizumab-related. Median oral corticosteroid (OCS) dose decreased from 6.9 (pre-mepolizumab) to 3.0 (baseline) and 2.0 mg/day (Weeks 45-48); the proportion of patients receiving no OCS increased from 8% to 32% and 38%, respectively. Patients experiencing clinical symptoms decreased from 94% (pre-mepolizumab) to 73% (baseline) and 67% (Week 48). During the observation period, 5% of patients experienced EGPA relapse; rates of EGPA-related hospitalisations, EGPA-related emergency room/unscheduled visits and asthma exacerbations were 0.05, 0.09 and 0.08 event/person-year, respectively.

Conclusions: : Results of mepolizumab treatment for ≥144 weeks (before baseline plus observation) were consistent with the known safety profile and allowed OCS dose reduction while improving disease control versus pre-treatment among patients with EGPA.

Keywords: ANCA-associated vasculitis; Churg-Strauss syndrome; biologic; corticosteroid-sparing; interleukin-5.