The purpose of this study is to evaluate the efficacy and safety of rapcabtagene autoleucel versus comparator in participants with severe active GPA or MPA. There will be two cohorts in this study. Participants in lead in cohort will receive rapcabtagene autoleucel. Participants in a randomized cohort will receive either rapcabtagene autoleucel or comparator. After end of the study, participants who received rapcabtagene autoleucel infusion will enter into a long term follow up period that lasts upto 15 years. This will be a separate protocol.

Who can Participate

Key eligibility- Men and women, aged 18 to 75 years with a diagnosis of GPA or MPA. Participants are excluded if they have any condition that could prevent a complete washout of medications or could otherwise make the participant ineligible for anti-CD19 CAR-T therapy and further participation in the study Key inclusion 1. Men and women, aged ≥18 and ≤ 75 years with a diagnosis of GPA or MPA 2. Positive test for ANCA-autoantibodies 3. GPA and MPA participants with severe active disease Key exclusion 1. Any condition that could prevent a complete washout of medications or could otherwise make the participant ineligible for anti-CD19 CAR-T therapy and further participation in the study 2. Hypersensitivity and/or contraindications to any product to be given to the participant as part of the study protocol 3. Other systemic autoimmune diseases requiring therapy 4. Any medical conditions that are not related to GPA/MPA that would jeopardize the ability of the participant to tolerate CD19 CAR-T cell therapy 5. Inadequate organ function

Study ID

More information available at ClinicalTrials.gov: NCT06868290