Effect of Reduced-Dose vs High-Dose Glucocorticoids Added to Rituximab on Remission Induction in ANCA-Associated Vasculitis

Importance

The current standard induction therapy for antineutrophil cytoplasm antibody (ANCA)–associated vasculitis is the combination of high-dose glucocorticoids and cyclophosphamide or rituximab. Although these regimens have high remission rates, they are associated with considerable adverse events presumably due to high-dose glucocorticoids.

Objective

To compare efficacy and adverse events between a reduced-dose glucocorticoid plus rituximab regimen and the standard high-dose glucocorticoid plus rituximab regimen in remission induction of ANCA-associated vasculitis.

Design, Setting, and Participants

This was a phase 4, multicenter, open-label, randomized, noninferiority trial. A total of 140 patients with newly diagnosed ANCA-associated vasculitis without severe glomerulonephritis or alveolar hemorrhage were enrolled between November 2014 and June 2019 at 21 hospitals in Japan. Follow-up ended in December 2019.

Interventions

Patients were randomized to receive reduced-dose prednisolone (0.5 mg/kg/d) plus rituximab (375 mg/m²/wk, 4 doses) (n = 70) or high-dose prednisolone (1 mg/kg/d) plus rituximab (n = 70).

Main Outcomes and Measures

The primary end point was the remission rate at 6 months, and the prespecified noninferiority margin was −20 percentage points. There were 8 secondary efficacy outcomes and 6 secondary safety outcomes, including serious adverse events and infections.

Results

Among 140 patients who were randomized (median age, 73 years; 81 women [57.8%]), 134 (95.7%) completed the trial. At 6 months, 49 of 69 patients (71.0%) in the reduced-dose group and 45 of 65 patients (69.2%) in the high-dose group achieved remission with the protocolized treatments. The treatment difference of 1.8 percentage points (1-sided 97.5% CI, −13.7 to ∞) between the groups met the noninferiority criterion (P = .003 for noninferiority). Twenty-one serious adverse events occurred in 13 patients in the reduced-dose group (18.8%), while 41 occurred in 24 patients in the high-dose group (36.9%) (difference, −18.1% [95% CI, −33.0% to −3.2%];P = .02). Seven serious infections occurred in 5 patients in the reduced-dose group (7.2%), while 20 occurred in 13 patients in the high-dose group (20.0%) (difference, −12.8% [95% CI, −24.2% to −1.3%];P = .04).

Conclusions and Relevance

Among patients with newly diagnosed ANCA-associated vasculitis without severe glomerulonephritis or alveolar hemorrhage, a reduced-dose glucocorticoid plus rituximab regimen was noninferior to a high-dose glucocorticoid plus rituximab regimen with regard to induction of disease remission at 6 months.

Trial Registration

ClinicalTrials.gov Identifier:NCT02198248