MO255 LONG-TERM MAINTENANCE TREATMENT WITH RITUXIMAB IN ANCA-ASSOCIATED VASCULITIS: A RETROSPECTIVE COHORT STUDY

Chalkia, Aglaia; Thomas, Konstantinos; Kourniotis, Dimitrios; Panagiotopoulos, Alexandros; Alexakou, Zoe; Mpora, Margarita; Aggelis, George; Vasilopoulos, Dimitrios; Petras, Dimitrios

BACKGROUND AND AIMS: There is limited guidance and evidence for the ideal duration of maintenance treatment in ANCA-associated vasculitis (AAV) with rituximab (RTX). This study aimed to describe the efficacy and safety of long-term maintenance treatment with RTX, in a cohort of patients with AAV. METHOD: Retrospective, descriptive study of 62 patients with AAV. We included 42 patients, who received RTX maintenance treatment in a newly diagnosed or a relapsed disease. We recorded the duration, dosage, and adverse events (infections, infusion-related events, relapses, late onset leukopenia, malignancy and hypogammaglobulinemia). RESULTS: 43 patients (average age 60.33 years, 49% women) received fixed interval dosing with RTX maintenance 1000 mg every 6 months. The most frequent organ involvement (74%) was lung and/or kidney. 33% (14/43) of the patients received RTX maintenance in a relapsed disease. The RTX regimen was followed after induction treatment with rituximab (47%), cyclophosphamide (33%), combination cyclophosphamide and rituximab (14%) or methotrexate/MMF (6%). Median total duration of maintenance treatment was 24 months (range 6-72 months). The most frequent adverse event was serious infections in 23% of the patients, including SARS-CoV-2 in two patients, while four of these patients died. We also recorded: hypogammaglobulinemia in 14%, malignancy in 5% and infusion-related events in 2%. The rate of the major relapses in our cohort during RTX maintenance was quite low at 7% (3/43), the time between 24-60 months, and the rate of the major relapses dependent on the induction treatment was quite the same: cyclophosphamide group vs rituximab group (7 vs 10%, p=0.786). CONCLUSION: In our cohort long-term maintenance treatment in AAV with rituximab maintains remission for longer time, with a quiet safety profile. This could suggest that in selected patients, extended periods of rituximab treatment might be safe.