Table 1: Critical RAVE Trial Definitions

Clinical remission Having a BVAS/WG = 0, regardless of immunosuppressive therapy.
Complete response Having a BVAS/WG = 0 on low dose prednisone and on maintenance AZA/AZA placebo.
Remission Having a BVAS/WG = 0.
Complete remission Having a BVAS/WG = 0 and being off glucocorticoid therapy.
Partial remission Having a BVAS/WG ≤ 2 and being off glucocorticoid therapy during the trial.
Sustained remission Complete remission for at least 6 months.
Clinical tolerance Complete remission without immunosuppressive therapy, a normalized B-cell count, an absence of ANCA, and an adaptive immune system that responds normally to neoantigens.
Control arm The study treatment group receiving rituximab-placebo, CYC, AZA, and prednisone.
Crossover A change in treatment group to the opposite study therapy regimen between visit V5 (1 week after the last rituximab/rituximab-placebo infusion) and visit V8 (month-6 study visit).
Switchover Participants who do not deviate from original study therapy and all crossover participants that achieve clinical remissions (BVAS/WG = 0) deemed stable by the investigator will switch from CYC/CYC-placebo to AZA/AZA-placebo between months 3–6 after the first dose of the rituximab/rituximab-placebo infusion.
Disease response A reduction of at least 1 in the BVAS/WG as compared to the screening measure, no new disease manifestation, and no new worsening of existing disease.
Early treatment failure Failure to achieve disease response by the month 1 study visit, i.e., 1 week after the fourth infusion, or to complete the full course of rituximab/rituximab-placebo infusions due to treatment-related adverse effects.
Experimental arm The study treatment group receiving rituximab, prednisone, CYC-placebo, and AZA-placebo.
Investigational agent Rituximab (375 mg/m2)
Investigational regimen Rituximab (375 mg/m2) once a week x4, plus glucocorticoids
Limited flare Having a new occurrence or worsening of one or more minor BVAS/WG items.
Post-study phase The study period that starts after the last scheduled study visit in the remission maintenance phase (the 18-month study visit after V1 or V1A) and lasts until the common closing date. The post study phase for open-label rituximab patients starts 6 months after V1B.
Severe flare Having a BVAS/WG >3 or experiencing one of the major BVAS/WG items listed in Table 2 that requires treatment with CYC following remission (BVAS/WG = 0).
Pretreatment phase The study period that lasts approximately 2 weeks and that includes screening, signing of the informed consent form, receipt of intravenous steroids, and randomization.
Remission induction phase (phase I) The 6-month study period following randomization.
Remission maintenance phase (phase II) The 12-month study period following the remission induction phase.
Remission induction treatment Rituximab infusion (once weekly for 4 weeks) or rituximab placebo infusion (once weekly for 4 weeks), cyclophosphamide or cyclophosphamide placebo (orally for 3–6 months), and prednisone (orally for up to 6 months).
Remission maintenance treatment AZA or AZA placebo (orally for 12–15 months), depending on the timing of switchover from CYC/CYC placebo to AZA/AZA placebo).
Severe AAV Having a diagnosis of AAV (GPA or MPA) that meets the Chapel Hill Consensus Conference definitions, a positive PR3-ANCA or MPO-ANCA test, and disease activity/severity that requires treatment with CYC.
Study medications Rituximab or placebo, CYC or placebo, AZA or placebo.
Study therapy CYC/CYC placebo, AZA/AZA placebo, or rituximab/rituximab placebo.
Study termination Discontinuing the rituximab/rituximab placebo, CYC/CYC placebo, or AZA/AZA placebo study therapies as per protocol.
Treatment failure Situations that may lead to treatment modification as defined in the protocol.