Combination Cyclophosphamide and Rituximab to Minimize Glucocorticoid Use in Antineutrophil Cytoplasm Antibody-Associated Vasculitis.

INTRODUCTION

The optimal duration of immunosuppressive therapy for antineutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV) is uncertain. Glucocorticoids are a mainstay of treatment but are associated with significant morbidity. Here, we describe outcomes of a cohort of patients treated with combination cyclophosphamide and rituximab induction alongside a rapidly tapering oral-only glucocorticoid regimen.

METHODS

In this retrospective, observational, cohort study, we identified patients presenting with AAV between 2011 and 2023 treated with combination cyclophosphamide and rituximab induction therapy. We analyzed biochemical, histologic, and outcome data, including time-to-remission and relapse rate. A subgroup analysis compared outcomes based on glucocorticoid duration.

RESULTS

A total of 112 patients with active AAV treated with combination cyclophosphamide and rituximab were identified (median age: 67 years; 85% kidney involvement; baseline estimated glomerular filtration rate [eGFR] 24 ml/min per 1.73 m). Of the patients, 96% achieved remission; median time-to-remission was 77 (interquartile range [IQR]: 64-92) days. All patients demonstrated biochemical and histologic improvement following treatment. Five patients (5%) experienced a disease relapse over 2.9 (IQR: 1.7-4.3) years follow-up. The cumulative glucocorticoid dose was 1780 (IQR: 1141-2935) mg with median duration of 12.5 (IQR: 8.0-39.0) weeks. Patients treated with oral glucocorticoids for > 12 weeks received a higher cumulative dose (2935 vs. 1133 mg; < 0.001) with a trend toward more serious infections (21% vs. 7%; = 0.06) than those treated for 12 weeks with no differences in disease remission (100% vs. 91%; = 0.07) or relapse (9% vs. 0%; = 0.07) rates.

CONCLUSION

Early withdrawal of oral glucocorticoid therapy in patients with severe AAV treated with combination cyclophosphamide and rituximab induction immunosuppression is safe and effective and may reduce morbidity, in particular serious infections.