Early mepolizumab initiation during remission induction is associated with lower organ damage burden in EGPA: a multicentre cohort study.

Abstract

To evaluate whether early mepolizumab initiation during remission induction is associated with favourable clinical outcomes and lower organ damage burden in patients with eosinophilic granulomatosis with polyangiitis (EGPA). This retrospective multicentre cohort study used data from Kyushu Vasculitis Cohort Study. Patients with EGPA were classified into an early mepolizumab group, in which mepolizumab was initiated within 3 months of remission induction, and a conventional group. The primary endpoint was clinical remission at 1 year, defined as Birmingham Vasculitis Activity Score (BVAS)=0 with prednisolone ≤4 mg/day. Secondary endpoints included remission at 6 months and 2 years, glucocorticoid exposure, relapse, mortality and organ damage assessed by the Vasculitis Damage Index (VDI). Longitudinal VDI values from 6 months to 2 years were analysed using linear mixed-effects model. Sixty-four patients were included (early mepolizumab, n = 16; conventional, n = 48). Clinical remission at 1 year was achieved more frequently in the early mepolizumab group than in the conventional group (69% vs 27%; P = 0.006). At 2 years, remission was achieved in 10/10 (100%) versus 13/45 (29%) evaluable patients (P < 0.001), and glucocorticoid discontinuation in 4/10 (40%) versus 4/45 (9%) (P = 0.029). BVAS decreased markedly in both groups. Early mepolizumab initiation was associated with lower longitudinal VDI values (β = -0.36, 95% CI - 0.70 to - 0.03; P = 0.032). Early mepolizumab initiation was associated with higher remission rates, lower glucocorticoid exposure and lower organ damage burden during the first 2 years in EGPA.