Phase 2 Study of ALXN2030 in Patients With Antibody-Mediated Rejection After Kidney Transplantation

Inclusion Criteria: * Kidney transplant received ≥ 6 months * Active or chronic active AMR according to Banff 2022 classification, based on Screening kidney biopsy * Either positive C4d on Screening kidney biopsy based on the Central Pathology Laboratory report and/or positive HLA Class I and/or II antigen-specific DSA as determined by the local laboratory's definition of positivity using single-antigen bead based assays * MVI score ≥ 2 (g ≥ 1 and ptc ≥ 1) * eGFR ≥ 30 mL/min/1.73 m2 * Must be vaccinated against meningococcal infection from serogroups A, C, W, Y (and B where available) at least 14 days prior to but no more than 3 years prior to Day 1 * Must be vaccinated for S pneumoniae prior to randomization * Must be vaccinated for H influenzae type B (where available) prior to randomization * Body weight ≥ 50 kg at Screening Exclusion Criteria: * Biopsy-based diagnosis of any of the following at Screening: * TCMR, according to the Banff grade ≥ 1 * Polyoma virus nephropathy * Severe thrombotic microangiopathy * Glomerulonephritis * ABO-incompatible transplant * uACR \> 2200 mg/g * Multiorgan transplant recipient (except for previous multiple kidney transplants) or cell transplant (islet, bone marrow, stem cell) recipient * Planned or recent treatments, \< 3 months prior to the Screening Visit, for Acute Rejection, AMR (including plasmapheresis, plasma exchange, IVIg, B-cell depleting therapy, IL inhibitors, proteasome inhibitors, high-dose corticosteroids \[except for tapering\]), TCMR (including T-cell depleting therapy), excluding the SoC immunosuppressant treatment which will be allowed and should be stable during the entire treatment.