Desensitisation With Imlifidase Prior to Kidney Transplant in Highly Sensitised Children

The goal of this clinical trial is to learn about the efficacy and safety of imlifidase in highly sensitized paediatric patients, 1-17 years old, with end stage renal disease (ESRD).The main questions it aims to answer are:Does imlifidase treatment result in crossmatch conversion that enables transplantation?How is the function of the transplanted kidney?The participants will be hospitalised in accordance with the normal routines for transplanted patients. The patients will receive medication to prevent rejection of the donor kidney, and because such treatment make the body more vulnerable medications to prevent infections.

Inclusion Criteria:Signed Informed Consent obtained from patient/parent/legal guardian/independent witness (depending on patient's age) before any trial-related proceduresHighly sensitised patient with panel reactive antibodies (PRA) ≥80%Male or female patient between the age of 1 to 17 years (up to the day before the 18th birthday) at the time of screeningPatient with end-stage renal disease (ESRD) and waiting for a renal transplant from a living or deceased donorPatient must be transplantable (including size mismatch) at the time of obtaining informed consent for trial participationPatients who have previously undergone desensitisation unsuccessfully with plasmapheresis/IVIg/anti-CD20 or have an anti-HLA antibody status deemed too difficult to make a successful desensitisation (judgement based on physicians' previous experience with similar patients)Positive crossmatch (XM) test determined by flow cytometry crossmatch (FCXM) and/or complement-dependent cytotoxicity crossmatch (CDCXM) tests against the donor. For the DD patients, if physical XM tests are not practically possible due to lack of time, patients may be included on a virtual crossmatch (vXM) predictive of a positive XM test.Willingness and ability to comply with the protocol as judged by the investigatorExclusion Criteria:Previous treatment with imlifidaseIVIg treatment within 28 days prior to imlifidase treatmentDesensitisation treatment(s) within 1 month prior to the current transplantationHypersensitivity to the active substance (imlifidase) or to any of the excipients and to other immunosuppressive drugs specified in the protocolOngoing serious infectionsPresent, or history of, thrombotic thrombocytopenic purpura (TTP), or known familial history of TTPAt the time of transplantation: severe other condition requiring treatment and close monitoring e.g. cardiac failure ≥ grade 4 (New York Heart Association), unstable coronary disease, active peripheral vascular disease, proven hypercoagulable conditions/events or oxygen dependent respiratory diseaseMalignancy within 3 years prior to transplantationABO blood group incompatible transplantations (A2 and A2B kidneys will not be accepted for B recipients)Any other reason that, in the view of the investigator, precludes transplantationBreast feeding or pregnancy, if applicableWoman of fertile age and sexually active without adequate contraceptive measures to avoid pregnancy during the interventional trial period (i.e. up to 6 months after transplantation)Suspicion of Covid-19 infection or positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testPositive serology for human immunodeficiency virus (HIV)Clinical signs of hepatitis B virus (HBV), hepatitis C virus (HCV), cytomegalovirus (CMV), or Epstein Barr virus (EBV) infectionDonor with positive serology for HIV, HBV, HCV, CMV or EBV to a patient with negative serology (mismatch serology)Clinically relevant active infection(s) as judged by the investigatorTuberculosisUse of other investigational agents within 5 terminal elimination half-lives prior to the transplantationContemporaneous participation in medical device studiesKnown mental incapacity or language barriers precluding patients'/parents'/legal guardians' adequate understanding of the informed consent information and the trial activitiesInability by the judgement of the investigator to participate in the trial for any other reason