Maintenance of remission of ANCA vasculitis by rituximab dosed for B cell repopulation

A recent study suggests that dosing rituximab for B cell repopulation results in decreased clinical relapses during the maintenance of remission for ANCA vasculitis, in comparison to dosing based on an increase in ANCA level. This study’s findings were published in the Annals of the rheumatic diseases. 
This single-centre, open-label, randomised control trial enrolled 115 patients with ANCA vasculitis in remission after receiving at least 2 years of fixed-schedule rituximab. Rituximab was reinfused upon B cell repopulation in the B cell group, whereas rituximab was reinfused upon a significant increase in ANCA level in the ANCA group. Evaluations were conducted every 3 months, with the primary endpoint being clinical relapse, defined as a modified BVAS/WG >0 by 36 months. Secondary endpoints of the study included rituximab exposure and serious adverse events (SAEs). 
The median follow-up time of the study was 4.1 years (IQR 2.5 - 5.0). Utilizing Kaplan-Meier analysis, it was found that at the 3-year mark after study entry, 4.1% (95% CI 1.0 to 15.6) of patients in the B cell arm experienced a clinical relapse, while 20.5% (95% CI 11.9 to 34.1) of patients in the ANCA arm had a relapse. There were no significant differences in the total number of SAEs, including infectious SAEs and deaths, between the two arms. Patients in the B cell group received an average of 3.6 infusions (3.6 g) per person over the 4.1-year median follow-up period, compared to only 0.5 infusions (0.5 g) per patient in the ANCA group.
Therefore, it can be concluded that rituximab dosed for B cell repopulation may reduce the number of clinical relapses in comparison to when dosed to raise ANCA levels in the maintenance of remission for ANCA vasculitis.