Nation wide cohort study of Japanese patients with ANCA associated vasculitis using rituximab Effectiveness and safety after two years.

OBJECTIVES

To evaluate the efficacy and safety of rituximab (RTX) for microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) in Japan.

METHODS

Patients with MPA and GPA treated with RTX at each institution were enrolled and followed-up prospectively. Two years of data were analysed.

RESULTS

Seventy-five patients were received RTX for remission induction therapy and 57 were observed beyond 6 months. Thirty-five did and 22 did not receive any additional RTX treatment. RTX dosing patterns were diverse. During the 2-year observation period, 56 (74.7%) patients achieved remission; however, 11 (19.6%) patients relapsed. Five patients experienced major relapses, three experienced minor relapses, and three experienced unclassified relapses. Of the 75 patients treated with RTX as remission induction therapy, 63 severe adverse events (SAEs) were observed in 33 patients during the 2-year observation period. Thirty-nine SAEs occurred by 6 months and 24 SAEs were observed after 6 months. Of the 12 patients with SAEs after 6 months, four received RTX after 6 months, resulting in six events. The most common SAE was infection during the first 6 months and after 6 months.

CONCLUSIONS

The effectiveness and safety of RTX for MPA and GPA in Japan were demonstrated over a 2-year observation period.