Better EGPA Outcomes Associated With Early Mepolizumab

Early initiation of mepolizumab during remission induction was associated with higher clinical remission rates and a lower organ damage burden than conventional treatment in patients with eosinophilic granulomatosis with polyangiitis (EGPA), according to a multicentre cohort study published in Rheumatology.

The retrospective study used data from the Kyushu Vasculitis Cohort Study, an observational cohort across 14 institutions in Japan, to compare outcomes between patients who initiated mepolizumab within 3 months of starting remission induction (the early mepolizumab group) and those who did not (the conventional group). The primary endpoint was clinical remission at 1 year, defined as a Birmingham Vasculitis Activity Score (BVAS) of 0 with prednisolone 4 mg/day or less.

The analysis included 64 patients: 16 in the early mepolizumab group and 48 in the conventional group. Clinical remission at 1 year was achieved in 69% of the early group versus 27% of the conventional group (P=0.006); at 2 years, remission was achieved in 100% versus 29% of evaluable patients (P<0.001), and glucocorticoid discontinuation occurred in 40% versus 9% (P=0.029).

BVAS decreased markedly in both groups with no significant between-group difference. Early mepolizumab initiation was associated with lower longitudinal Vasculitis Damage Index values across the 2-year follow-up (β=-0.36; 95% CI, -0.70 to -0.03; P=0.032). Despite reduced vasculitis activity in both groups, peripheral neuropathy frequently persisted as irreversible damage. The authors noted the study's retrospective, observational design, small early-group sample size, and potential calendar-time bias, as early mepolizumab use occurred predominantly in more recent years.

The authors concluded that early mepolizumab initiation was associated with higher remission rates, lower glucocorticoid exposure, and lower organ damage burden during the first 2 years in EGPA, but said these findings should be interpreted as an association rather than a causal effect and require confirmation in prospective studies.

Source: Maruyama A, Ono N, Kai T, et al. Early mepolizumab initiation during remission induction is associated with lower organ damage burden in EGPA: a multicentre cohort study. Rheumatology. Published online 2026. doi:10.1093/rheumatology/keag523