Five Years Follow-up of Imlifidase Desensitized Kidney Transplant Recipients

In four phase 2 clinical trials, patients underwent imlifidase-enabled kidney transplantation, converting a positive crossmatch (+XM) to negative. Here, we present data from 39 patients enrolled in the 5-year follow-up extension trial. Patient survival, graft survival, renal function, delayed graft function (DGF) antibody mediated rejection (AMR) frequency, safety and presence of donor specific antibodies (DSAs) are presented. Data from the long-term follow-up trial (17-HMedIdeS-14); NCT03611621) with planned visits at 1, 2, 3, and 5 years after imlifidase were combined with up to 6-month phase 2 data from 4 pivotal trials (13-HMedIdeS-02, 13-HMedIdeS-03, 14-HMedIdeS-04, 15-HMedIdeS-06). Five-year patient survival was 90% with 3 deaths occurring between 6 months and 1 year, with no deaths occurring subsequently. Death-censored graft survival was 82% (with 3 early graft losses and 3 graft losses between 2 and 5 years). Mean eGFR at 5 years was 50.1 (MDRD), 55.8 (CKD-EPI, 2021) and 52.5 (KRS, 2023) mL/min/1.73 m² (N = 24 patients) among functioning grafts. DSA rebounded with levels progressively decreasing over time and no increase in DSA seen between 3 and 5 years. No AMR occurred between 3 and 5 years. Furthermore, no additional safety signals assessed as related to imlifidase were reported in this cohort. At 5 years, highly-HLA sensitized patients who underwent imlifidase desensitization prior to transplantation demonstrated excellent patient and graft survival, despite their high-risk immunological profile. Imlifidase offers a viable and effective treatment option for highly sensitized patients to achieve life-saving transplantation and continued optimism is warranted.

ClinicalTrials.gov (NCT02790437), EudraCT Number: 2016-002064-13.