Following induction of remission with rituximab, repeat-dose rituximab was superior to azathioprine for preventing disease relapse in patients with antineutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV) with a prior history of relapse, according to a study published in the Annals of the Rheumatic Diseases.

In RITAZAREM, an international randomized controlled, open-label, superiority trial, the researchers recruited 188 patients with AAV in relapse between April 2013 and November 2016.

The patients were initially treated with rituximab and glucocorticoids to re-induce remission. When remission was achieved, 85 randomized patients were administered rituximab intravenously (1000 mg every 4 months, through month 20) and 85 remaining participants received oral azathioprine (2 mg/kg/day, tapered after month 24).

The study authors monitored the time to minor or major disease relapse as the primary outcome measure. All patients were followed up for at least 36 months.

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According to the study results, rituximab was superior to azathioprine in preventing relapse. During the maintenance phase, 13 of 85 (15%) patients in the rituximab group experienced a relapse compared with 32 of 85 (38%) patients in the azathioprine group.

During the follow-up phase, there were 33 relapses in 25 patients from the rituximab group compared with 49 relapses in 28 patients from the azathioprine group. Five patients in the rituximab group experienced a major relapse during the follow-up period compared with 11 patients in the azathioprine group.

Nineteen patients (22%) of 85 in the rituximab group experienced at least 1 serious adverse event during the treatment period compared with 31 (36%) of 85 patients in the azathioprine group.

“Serious adverse events and infections were common, consistent with previous studies in AAV, and there were no new safety signals for these medications in this population. Hypogammaglobulinaemia, secondary immunodeficiency, and impaired vaccine responses are a concern with the use of repeated doses of rituximab,” Smith and colleagues wrote.

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“Furthermore, after discontinuation of therapy, relapses were frequent in both groups indicating that the benefit of rituximab, even at a high dose, was not sustained beyond the treatment period.”

Frequent disease relapses in AAV might be linked to increased exposure to immunosuppressive medications, the accrual of damage, and increased morbidity and mortality.


Smith RM, Jones RB, Specks U, et al. Rituximab versus azathioprine for maintenance of remission for patients with ANCA-associated vasculitis and relapsing disease: an international randomised controlled trial. Ann Rheum Dis. Published online March 23, 2023. doi:10.1136/ard-2022-223559