Fixed-interval, repeat-dose rituximab is an effective maintenance therapy for patients with ANCA-associated vasculitis, a retrospective study reports.
The study helps to inform the ideal duration of maintenance treatment and the effects of cumulative treatment of ANCA (antineutrophil cytoplasmic antibody)–associated vasculitis (AAV) with the anti-CD20 monoclonal antibody rituximab, which is one of the currently unknown factors in the biologic’s use as an induction and maintenance treatment, according to the study authors, led by Dr. Federico Alberici from the University of Cambridge (England) (Rheumatology 2014 Dec. 3 [doi:10.1093/rheumatology/keu452]).
Current evidence suggests that maintenance therapy in AAV should be continued for 18-24 months, but the risk of relapse is high with standard maintenance treatment with first-line agents, they noted.
The researchers followed 69 AAV patients who received fixed-interval, repeat-dose rituximab for 2 years.
For initial remission induction, patients received rituximab 1 g every 2 weeks or 375 mg/m2 weekly for 4 consecutive weeks. Remission maintenance was 1 g every 6 months for 24 months.
At the first rituximab dose, ongoing immunosuppressives were withdrawn and prednisolone was tapered during follow-up, with the aim of achieving complete withdrawal or 5 mg/day.
During the treatment protocol, nine patients (13%) relapsed at a median of 11 months after the first rituximab infusion, the researchers reported.
However, by the end of the maintenance phase, all 69 patients were in remission; 33 patients (48%) were not receiving steroids and 63 patients (91%) were not receiving other immunosuppressants.
During the posttreatment follow-up, 28 patients relapsed a median of 34.4 months after their last rituximab infusion.
Relapse risk was higher in patients who had a return of B cells within 12 months of the last rituximab dose (P = .0052), a switch from ANCA negativity to positivity (P = .0046), and PR3-associated disease (P = .039), the researchers reported.
“In order to allow early identification of major relapses in patients not on immunosuppression, we recommend monitoring B cells and ANCA after rituximab withdrawal,” they wrote.
“Better biomarkers are required to identify patients at relapse risk after rituximab maintenance therapy withdrawal,” they added.
The study was supported by the National Institute of Health Research Cambridge Biomedical Research Centre. Two authors reported receiving lecture fees and/or a research grant from Roche/Genentech, the manufacturer of rituximab. Another