Rituximab and Cyclophosphamide Remission Induction Have Similar Kidney Failure, Mortality Risk in AAV

In antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), both rituximab- and cyclophosphamide-based remission induction were found to be associated with similar kidney failure and mortality risks, according to study findings published in Arthritis & Rheumatology.

In the last 2 decades, treatment for AAV has evolved and led to substantial improvements in outcomes; however, patients with AAV continue to have high risk for kidney failure and mortality.

Researchers from Boston conducted a study using real-world data from the Mass General Brigham (MGB) AAV cohort.

Patients who were diagnosed with AAV between 2002 and 2019 and received rituximab- or cyclophosphamide-based remission induction were evaluated for kidney failure and all-cause mortality outcomes.

The study cohort included a total of 595 patients, with 352 (60%) receiving rituximab– and 243 (40%) receiving cyclophosphamide-based remission therapy. The patients had a mean age of 61 (SD, 17) years; 58% were men; 87% were White; and had a Birmingham Vasculitis Activity Score (BVAS) or Wegener’s Granulomatosis (GPA) score of 5.1 (SD, 2.2) points.

Stratified by treatment, the rituximab vs cyclophosphamide recipients had significantly higher BVAS/GPA scores (mean, 5.4 vs 4.8 points; P <.001) and lower erythrocyte sedimentation rates (median, 16 vs 24 mm/hr; P <.001).

The composite rate of kidney failure and all-cause mortality occurred among 43 rituximab and 36 cyclophosphamide recipients at 1 year (adjusted hazard ratio [aHR], 0.86; 95% CI, 0.42-1.76), 56 and 42 patients at 2 years (HR, 0.85; 95% CI, 0.42-1.72), and 75 and 58 patients at 5 years (HR, 1.03; 95% CI, 0.55-1.93), respectively.

Results were similar in the propensity score-matched and adjusted propensity score-matched analyses.

In subgroup analyses, risk for kidney failure and all-cause mortality was not associated with treatment at 1, 2, or 5 years among the subset of patients with kidney involvement (n=412), severe kidney involvement (n=168), major involvement (n=477), and those with myeloperoxidase-negative (MPO-) ANCA-positivity (n=415).

In the sensitivity analysis that excluded patients who received an oral cyclophosphamide bridging course before starting rituximab, no deviations in trends were observed.

The limitations of the analysis included the retrospective design and the fact that data were sourced from a single health care organization in 1 city, which may have limited the generalizability of findings.

The study authors concluded, “[W]e found that the risk of kidney failure or death was similar with rituximab and cyclophosphamide for remission induction in patients with AAV over [5] years of follow-up.” They added, “Additional studies are needed to investigate differences in risk for other relevant clinical outcomes over longer time horizons, such as drug toxicity.”

Disclosures: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of author’s disclosures.