A few points to consider:
· Regarding the relevancy of the results for nephrologists, it must be noted that only 66% had renal involvement and creatinine clearance was 54-69mls/min in the 2 groups. The mean increase in creatinine clearance was similar at approximately 11mls/min in both groups and response rate was similar between the 2 groups in patients with ‘severe’ renal disease.
· Rituximab is often considered a ‘clean’ drug. What strikes me after reading many studies using rituximab is that the adverse event rate is usually similar to the comparison group, in this case cyclophosphamide.
· A persistent concern with rituximab is whether or not to re-treat, and if so when, after B cell re-population occurs. In this 18 month follow-up, non-inferiority was maintained at up to 18 months, when most patients in the rituximab group had reconstituted B cells. However, B cells were detectable in 88% of rituximab patients who relapsed between 6-18 months.
Verdict: A knowledge gap may still exist for patients presenting with a rapidly progressive GN requiring dialysis although the RITUXIVAS trial contained patients with worse renal function, some needing dialysis, and suggested equivalent early outcomes (but compared to IV cyclophosphamide). Also, we lack clarity on whether to re-treat and if steroids are necessary with rituximab. Overall, however, there is robust evidence that a 4 week course of rituximab is non-inferior to cyclophosphamide in the treatment of (most?) AAV patients.