The MAINTANCAVAS study, short for “Maintenance of ANCA Vasculitis Remission by Intermittent Rituximab Dosing,” was a clinical trial aimed at determining the best strategy to maintain remission in patients with ANCA vasculitis who have previously been treated with rituximab-induced B cell depletion. This study was designed as an interventional clinical trial with 115 participants and was conducted in a randomized, open-label, parallel assignment manner.

The trial had two arms. In the first arm, patients received intermittent B cell depletion with rituximab re-dosing upon B cell return, specifically when peripheral B cells reached or exceeded 10 B cells/mm³. In the second arm, rituximab was re-dosed upon a significant rise in ANCA titer, with specific thresholds set for different ANCA types. Patients in both arms were monitored regularly, with clinic visits every three months.

Key findings from the study showed that rituximab dosing based on B cell return was highly effective at preventing relapses compared to dosing based on ANCA titer. However, the B cell driven strategy was associated with a higher rate of serious adverse events (SAEs), including infections and a particular note of higher COVID-19 complications. Despite the increased SAEs, the B cell strategy proved to have better relapse-free survival rates at 48 months compared to the ANCA titer strategy.

Overall, the study concluded that while the B cell repopulation approach led to fewer clinical relapses and offered a better relapse-free survival rate, it also increased the risk of serious infections, which is an important factor to consider in the management of patients with ANCA vasculitis.