An Efficacy and Safety Study of Imlifidase in Treatment of Antibody-Mediated Rejection in Kidney Transplant Patients

Antibodies to human leukocyte antigens (HLAs) have a strong correlation with allograft injury and loss. Treatment with imlifidase, PE and immunoabsorption (IA) all aim to reduce antibody levels. This study compared the reduction in DSA levels after treatment with imlifidase and PE in patients diagnosed with active or chronic active AMR (according to Banff 2017 or Banff 2019 criteria) having at least a 25% rise in serum creatinine compared with last measurement prior to the AMR. (Patients with delayed graft function and AMR within 10 days after kidney transplantation could be included regardless of serum creatinine level.) Eligible patients were randomized to either 1 dose of imlifidase (0.25 mg/kg) or 5-10 sessions of PEs (IA could replace PE at the discretion of the investigator). All patients received pulse methylprednisolone Day 1 to Day 3, followed by a tapering schedule with prednisolone/prednisone. Patients randomised to imlifidase received their first dose of methylprednisolone before imlifidase was administered. The patients did also receive high dose intravenous immunoglobulin (IVIg) 3 days after imlifidase treatment or directly after the last PE. In addition a single dose of rituximab was given 5 days after completed IVIg infusion.