Induction therapy with rituximab enables sustained remission in elderly patients with relapsed anca-associated vasculitis: a retrospective analysis from j-canvas, a japanese multicentre-cohort

Background Rituximab (RTX) is widely used in both remission induction and maintenance therapy for the new-onset ANCA-associated vasculitis (AAV)[1]. However, few studies have reported the efficacy and safety of RTX against relapsed AAV, especially in elderly patients. Objectives To clarify the effectiveness and safety of RTX as a remission induction therapy after relapse in elderly AAV. Methods We retrospectively extracted elderly (≥65 years) patients who relapsed granulomatosis with polyangiitis or microscopic polyangiitis and received remission induction therapy from J-CANVAS, a Japanese multicentre-cohort. The main exposure was the usage of RTX in the therapy. Clinical and laboratory variables at relapse and complete remission (CR) rates at week 24 and 48 after starting induction therapy were compared between patients treated with RTX (RTX group) and those with the other conventional immunosuppressive therapies (non-RTX group). The primary outcome was the CR rates at week 24, which was defined as Birmingham Vasculitis Activity Score (BVAS) version3 = 0. In addition, we performed a multivariate logistic regression analysis after adjusting for the potentially confounding factors of age, AAV-subtype, and ANCA-serotype. Patients whose data were missing at week 24 or 48 were treated as non-CR. Results A total of 71 patients were enrolled; 30(42%) in RTX group and 41(58%) in non-RTX group. Baseline characteristics were comparable between two groups as shown in Table1. The median age was 74 vs. 76 years with the PR3-ANCA positivity rate of 23% vs. 17%, and the median BVAS score was 11 vs. 12 points, respectively. The CR rate at week 24 was higher in the RTX group than in the non-RTX group [21(70.0%) vs 27(65.8%), p = 0.308)] and that at week 48 was significantly higher in the RTX-group [24(80.0%) vs 19(46.3%), p = 0.004)] (shown in Figure 1), with comparable doses of concomitant glucocorticoids. The adjusted odds ratios of RTX use for CR at week 24 and 48 were 1.09 (95%CI 0.38-3.10) and 4.01 (95%CI1.29-12.30). The incidence of serious infection was similar in both groups: [4(13.3%) vs 4(9.8%), p=0.638)]. Conclusion RTX may be superior, with well tolerability, to the other conventional immunosuppressive therapies as an induction therapy in elderly patients with relapsed AAV. References [1]Chung, S.A et al. Arthritis Care Res 73, 1088-1105(2021) Table 1: Baseline characteristics of the enrolled patients Overall (N=71) RTX group (N=30) Non–RTX group (N=41) P-value Age (years), median (IQR) 75(71-80) 74(71-80) 76(71-82.5) .263 Sex (female), n (%) 37(52.1) 13(43.3) 24(58.5) .205 AAV subtype, n (%) .133 GPA 26(36.6) 14(46.7) 12(29.3) MPA 45(63.4) 16(53.3) 29(70.7) ANCA serotype, n (%) .782 PR3-ANCA 14(19.7) 7(23.3) 7(17.1) MPO-ANCA 54(76.1) 22(73.3) 32(78.0) both negative 3 (4.2) 1(3.3) 2(4.9) Glucocorticoid dose (PSL equivalent), median(IQR) 9(5-15) 8.3(5-11.8) 10(5.5-15) .373 Prior treatment regimen, n(%) Cyclophosphamide 4(5.6) 3(10.0) 1(2.4) .172 Mycophenolate mofetil 14(19.7) 2(6.7) 2(4.8) .747 Azathioprine 18(25.4) 10(33.3) 8(19.5) .186 Methotrexate 3(4.2) 2(6.7) 1(2.4) .382 Mizoribine 5(7.0) 1(3.3) 4(9.8) .296 Figure1 : Disease status and outcome of the enrolled patients Acknowledgements: NIL. Disclosure of Interests None Declared.