A Trial of Felzartamab in Kidney Transplant Recipients With Late Antibody-Mediated Rejection (AMR)

Eligibility Criteria

• * Active or chronic active AMR (biopsy-confirmed) without TCMR per central reading, as defined by the Banff 2022 criteria.
• * Kidney transplant at least 6 months prior to Screening visit (recipients of either living or deceased donors).
• * Donor-specific antibody (DSA): Human leukocyte antigen (HLA) Class I and/or II antigen-specific DSA-positive (pre-formed and/or de novo DSA) as determined by the local laboratory's definition of positivity using single-antigen bead-based assays within 6 months prior to randomization.
• * Transplant: Blood type (ABO)-incompatible transplant.
• * History of multiple organ transplants including en bloc and dual kidney transplants.
• * Acute, rapid decline in renal function, defined as a participant likely to require renal replacement therapy within the subsequent 30 days as determined by the Investigator.
• * Treatment: Prior AMR/TCMR treatment (with the exception of corticosteroids) within 3 months prior to randomization is excluded as listed below. Participants who received any of these treatments between 3 and 6 months prior to randomization must have both a renal biopsy (IC3) and DSA testing at least 6 weeks after completing (or stopping) treatment in order to confirm continuing AMR and to determine eligibility:
• 1. Intravenous or subcutaneous immunoglobulin (IVIg or subcutaneous immunoglobulin \[SCIg\]) or PLEX.
• 2. Complement system inhibitors (e.g., eculizumab).
• 3. Proteasome inhibitors (e.g., bortezomib).
• 4. Tocilizumab.
• 5. Any other investigational agent within 3 months or 5 half-lives (whichever is longer) of randomization.