This study is a prospective, open-labelled, randomized, controlled, single-center clinical trial. The aim of this study is to investigate the remission rate of patients treated with Telitacicept combined with Rituximab in remission-induction and Telitacicept alone in remission-maintain treatment.

Background: The basic theme of AAV is relapse and remission. The maintenance therapy of AAV aimed to reduce or prevent relapse is very challenge. Although many medications have been used for the maintenance of AAV, Telitacicept (a BAFF/APRIL dual-target-inhibitor, which has been proved to be effect in treatment of SLE) has not been studied yet. One study tested the efficacy of Belimumab in the maintenance therapy for AAV. When taken Rituximab as remission-induction treatment, no relapse was observed. However, the sample size of this study is small, and the Belimumab, as a BAFF inhibitor, was not been proved to have effect on APRIL.

Many experiences have been accumulated about the efficacy and safety of Telitacicept in Chinese patients with rheumatic diseases. But there is no study to show its effectiveness in the reduction of the relapse of AAV in China. In this study, we take Telitacicept as maintain treatment in AAV patients who receive Rituximab as remission-induction treatment, to verify the effectiveness of Telitacicept in maintenance therapy of AAV.

Objectives: To investigate the effectiveness of Telitacicept in reducing relapse rate by using from remission-induction treatment combined with Rituximab to maintenance treatment of AAV.

Study Design: This is a prospective, randomized, open-label, control, pilot study.

Inclusion Criteria:

1. Patients age 18 to 65 years, both genders can be included.
2. Patients who are newly diagnosed or relapsing granulomatosis with polyangiitis or microscopic polyangiitis must fulfill the 2022 ACR/EULAR classification criteria of GPA or MPA.
3. Patients have severe active AAV according to the 2021 ACR/vasculitis foundation definition.
4. Patients have to be PR3-ANCA-positive at diagnosis or during the course of their disease.

Exclusion Criteria:

1. Patients who had been treated with Rituximab but had to stop due to adverse events or intolerance.
2. Patients who had other autoimmune diseases.
3. Patients with severe liver dysfunction (defined as the 2-folds elevation of normal upper limit or Child grade III), heart failure or ESRD (eGFR<30ml/min).
4. Patients who are pregnant or have planned for pregnancy in next 2 years.
5. Patients with uncontrolled sever hypertension, diabetes, active bacteria or fungal infection.
6. Patients with active hepatitis virus infection as well as patients who have active mycobacteria infection.
7. Patients with malignancy.
8. Patients who are not eligible according to the judge of the principal investigators.

Only patient clincial information coud be released to public