Rituximab therapy achieves comparable remission to cyclophosphamide in ANCA-associated vasculitis with severe kidney involvement.

BACKGROUND: The RAVE (Rituximab versus Cyclophosphamide for ANCA-Associated Vasculitis) and RITUXIVAS (Rituximab versus Cyclophosphamide in ANCA-Associated Renal Vasculitis) trials established rituximab (RTX) therapy in antineutrophil cytoplasmic antibody-associated vasculitis (AAV). However, RAVE excluded patients with severe renal involvement (creatinine >354 µmol/L). Whilst RITUXIVAS did not, treatment included RTX with two cyclophosphamide (CYC) pulses. This study reports outcomes in AAV patients with severe renal involvement treated with RTX alone compared with CYC, together with high-dose steroids. METHODS: Data were collected retrospectively for all consecutive AAV presentations with severe renal involvement (peak creatinine >354 µmol/L) between 2010 and 2023 from two renal units. The primary outcome was sustained remission with independent renal function at 12 months. RESULTS: Amongst 107 de novo AAV patients, 66 received pulsed CYC with steroids [39 received plasma exchange (PLEX)], and 41 received RTX with steroids (7 received PLEX). At presentation, there was no significant difference in renal replacement therapy requirement (CYC 56% vs RTX 71%; P = .129), peak creatinine (511 vs 538 µmol/L; P = .399) or estimated glomerular filtration rate (eGFR) (9 vs 7 mL/min/1.73 m2; P = .372). Fifty-two percent of CYC patients and 49% of RTX patients met the primary outcome (P = .783). At 12 months, there was no significant difference in the proportion of patients with independent renal function (CYC 65% vs RTX 56%; P = .582), eGFR was similar between CYC and RTX patients (28 vs 31 mL/min/1.73 m2; P = .439), and 94% of the CYC cohort were alive compared with 83% of the RTX cohort (P = .068). CONCLUSION: RTX with steroids is comparable to CYC with steroids for successfully inducing remission in AAV with severe renal involvement.