Predictors of glucocorticoid-free clinical remission in patients with newly diagnosed microscopic polyangiitis and granulomatosis with polyangiitis: a retrospective cohort study using a nationwide registry in Japan (J-CANVAS)

Glucocorticoids (GC) comprise a cornerstone in the treatment of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV); however, prolonged GC exposure leads to substantial toxicity and immune system-related complications. Hence, identifying treatment strategies that enable early GC withdrawal while maintaining disease control is of clinical importance. To investigate the proportion and characteristics of patients achieving GC-free clinical remission (GFCR) 48 weeks after treatment initiation in patients with newly diagnosed microscopic polyangiitis (MPA) or granulomatosis with polyangiitis (GPA) and examine their long-term clinical outcomes (up to week 96). We conducted a retrospective cohort study using clinical data from a multicenter, nationwide registry in Japan comprising patients with newly diagnosed MPA or GPA and at least 48 weeks of follow-up. GFCR was defined as a Birmingham Vasculitis Activity Score (BVAS) of 0 with complete GC withdrawal. Univariable and multivariable logistic regression analyses were used to identify independent predictors of GFCR at week 48, and a sensitivity analysis using a matched cohort was performed to validate robustness. A total of 728 patients were enrolled in the registry, of whom 544 were followed for ≥ 48 weeks; among them, 29 (5.3%) achieved GFCR at week 48. Use of rituximab (RTX) for induction therapy and avacopan within 48 weeks were independently associated with achieving GFCR (multivariable analysis, model 1: RTX: odds ratio [OR]: 3.9, 95% confidence interval [CI]: 1.5–10.0; avacopan: OR: 24.3, 95% CI: 5.8–101.9; both p < 0.01). Conversely, methylprednisolone pulse therapy was associated with a lower likelihood of achieving GFCR (multivariable analysis, model 1: OR: 0.08, 95% CI: 0.02–0.44; p < 0.01). Patient’s demographic and baseline disease characteristics were not predictive of GFCR. In the long-term (weeks 48 through 96), the rates of death, relapse, and serious infection were similar regardless of GFCR status at week 48. The use of RTX for induction therapy and avacopan within 48 weeks is independently associated with achieving GFCR at week 48 in patients with MPA and GPA, supporting their potential as key components of GC-sparing strategies in AAV. Prospective studies are needed to confirm these results and optimize treatment algorithms to ensure disease control and minimize GC-related toxicity.