Highly Sensitized Patients Awaiting Kidney Transplant

This investigator-initiated, single-arm, open-label Phase IIa pilot study will evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary efficacy of OM336 in highly HLA-sensitized adults with chronic kidney disease awaiting kidney transplantation. The study will enroll 12 participants who have either a very low likelihood of receiving a compatible deceased donor kidney because of broad HLA sensitization or unacceptable donor-specific antibodies against a potential living donor. Participants will receive one 4-week course of subcutaneous OM336, with the option of a second 4-week course based on the change in virtual panel-reactive antibody (vPRA) levels after the initial treatment period. Participants will subsequently be followed for up to 24 months and, if transplantation occurs, for at least 12 months after transplantation. The primary objectives are to evaluate the safety and tolerability of OM336 through Week 24 and (co-primary endpoint) its effect on HLA sensitization, assessed by changes in vPRA levels at Week 24. Secondary and exploratory objectives include assessment of the durability of changes in vPRA and donor-specific antibodies, the number of potential compatible donors, transplantation rates, OM336 pharmacokinetics and immunogenicity, and effects on B-cell and plasma-cell immunity and antibody characteristics. An optional substudy will assess B-cell immunity in bone marrow and lymph-node samples.

The purpose of this clinical trial is to evaluate whether a temporary reprogramming of the immune system can help highly sensitized (hyperimmunized) patients with end-stage kidney disease safely receive a compatible kidney transplant. Patients who are highly sensitized have developed an extremely high level of antibodies against human leukocyte antigens (HLA), often due to previous transplants, pregnancies, or blood transfusions. This condition makes it nearly impossible for them to find a compatible organ donor, leaving them stuck on dialysis indefinitely. This study tests an innovative strategy using Autologous Hematopoietic Stem Cell Transplantation (AHSCT). The procedure involves an intensive conditioning regimen using a combination of medications (cyclophosphamide, thymoglobulin, and rituximab) to deeply clear out the patient's existing mature immune cells. This is followed by the reinfusion of the patient's own previously collected and purified blood stem cells (CD34+ cells) to rebuild the immune system from scratch. The investigators hypothesize that this procedure will eliminate the "immunological memory" cells responsible for producing the problematic anti-HLA antibodies, resetting the immune system to a "naive" or inactive state. This immune reset is expected to eliminate or significantly lower circulating HLA antibodies, creating a critical window of opportunity for these patients to successfully receive a compatible kidney transplant from the deceased-donor waiting list.

The purpose of this study is to assess the safety, tolerability, and efficacy of AZD0120 in highly sensitized adult participants with ESKD awaiting kidney transplant-who, as assessed by investigators, are improbable desensitization through conventional treatments (e.g., plasmapheresis and immunoadsorption)- with or without living donors.