Rituximab maintenance superior to azathioprine in ANCA-associated vasculitis

Comparing rituximab head-to-head to the current standard treatment with azathioprine for relapsing ANCA-associated vasculitis resulted in improved results for patients with rituximab [1].

Without maintenance therapy, relapses are common in anti-neutrophilic cytoplasmic autoantibody (ANCA )-associated vasculitis (AAV). “We started using maintenance rituximab for AAV around 2006,” said Dr Rona Smith (University of Cambridge, United Kingdom). The drug is already known as an effective treatment for AAV. “We used 2 grams initially, then 1 gram every 6 months for 2 years. Relapse rates were considerably reduced with the repeat dosing. But historically, azathioprine has been a standard for relapsing disease.

The RITAZAREM trial compared these approaches head-to-head,” Dr Smith explained. A total of 170 AAV patients in remission were randomised 1:1 to receive either 1,000 mg rituximab every 4 months for 5 doses or 2 mg/kg of azathioprine per day. Primary endpoint was time to relapse. Follow-up was done over at least 36 months. Baseline characteristics included a median age of 59 years, past disease duration 5.3 years, 28% patients who were positive for myeloperoxidase ANCA, and 72% positive for anti-proteinase 3 ANCA.

Results showed that at 20 months from randomisation 13% of patients in the rituximab arm had suffered from a relapse, in contrast to 38% in the azathioprine group. These relapses were categorised as ‘major’ in 18% (rituximab) versus 38% (azathioprine) of cases. Severe adverse events ≥1 appeared in 22% of rituximab-treated patients and 36% under azathioprine. The rate for serious infections was also lower with rituximab. “We would like to see these findings reflected in clinical practice. However, we recognise that rituximab is more expensive than azathioprine, which may affect how it is actually used in relapsing disease across the globe,” Dr Smith expressed.

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   1. Smith R, et al. Abstract 0806. ACR 2019. 8-13 November, Atlanta (GA/USA).

Posted on 4 February, 20204 September, 2023