This clinical trial investigates the transplantation of donor kidneys that have been genetically modified ex vivo using CRISPR-Cas9 genome editing to reduce immunogenicity and transplant rejection. Donor kidney grafts will have key human leukocyte antigen (HLA) genes disrupted - specifically, knockout of HLA class I heavy chains HLA-A and HLA-B, along with disabling HLA class II expression by targeting the CIITA gene (a master regulator of HLA-DR/DQ/DP). Approximately 90 adult end-stage renal disease patients will receive a CRISPR-edited donor kidney transplant. The primary objectives are to assess the safety and feasibility of this novel intervention, while secondary objectives evaluate the reduction in immune responses (immunogenicity), graft function, and the practicality of implementing ex vivo gene-edited organ transplantation in humans. By knocking out major donor HLA molecules, the trial aims to reduce T-cell and antibody-mediated recognition of the graft, potentially lowering rejection rates and reliance on high-dose immunosuppressants. Safety, including any off-target effects or unanticipated immune reactions, will be closely monitored, and transplant outcomes will be tracked for one year post-transplant.
In organ transplantation, differences in HLA genes between donor and recipient are a primary driver of allorecognition and graft rejection. Mismatched donor HLA antigens are identified as "non-self" by the recipient's immune system, provoking CD8\<sup\>+\</sup\> cytotoxic T lymphocyte responses, CD4\<sup\>+\</sup\> T-helper responses, and natural killer (NK) cell activation that can damage the graft. While immunosuppressive drugs can mitigate rejection, patients remain at risk for rejection if donor HLAs are unfamiliar, and life-long immunosuppression carries significant morbidities (infection, malignancy, etc.). Complete HLA matching is rarely achievable for all patients, especially for highly sensitized individuals with pre-formed anti-HLA antibodies. To address this, researchers have proposed rendering donor tissues "hypoimmunogenic" by removing or reducing expression of the most immunogenic HLA molecules. Preclinical studies show that eliminating key HLA class I and II antigens can prevent immune recognition and rejection of allogeneic cells. For example, genome editing of induced pluripotent stem cells to knock out HLA-A, HLA-B, and HLA-DR (via the DRA gene) successfully created universal cell grafts that evade T cell responses. Similarly, in animal models, silencing of major histocompatibility complex (MHC) genes in donor organs dramatically prolonged transplant survival. In a recent porcine study, donor lungs with reduced MHC (SLA gene) expression had markedly improved outcomes: \~71% of treated pigs survived long-term (2 years) with little to no rejection, whereas all control pigs receiving unmodified organs rejected within 3 months. Treated animals showed reduced donor-specific antibody production and T-cell reactivity, demonstrating that lowering graft antigenicity can ameliorate rejection. These findings provide a strong rationale that knocking out donor HLA genes can reduce human allograft immunogenicity and potentially allow better graft survival with less immunosuppression. This trial is a applying ex vivo CRISPR-Cas9 gene editing to donor organs to reduce HLA expression prior to transplantation. The editing strategy targets the donor kidney's HLA class I and II pathways: both HLA-A and HLA-B genes will be knocked out (biallelic disruption), while HLA class II expression is ablated by knocking out CIITA, a transcriptional activator required for HLA-DR, -DQ, and -DP expression. The intended result is a kidney graft largely devoid of classical HLA class I and II molecules. Notably, HLA-C (a class I gene) may be partially retained (e.g. only one allele knocked out) to maintain a low level of class I expression - this strategy can help avoid NK cell-mediated "missing-self" responses that occur when all class I is absent. By preserving minimal HLA-C or non-polymorphic HLA-E/G expression, the graft may evade NK cell attack while still lacking the highly polymorphic HLA-A/B and class II antigens that elicit T-cell and antibody responses. The overall hypothesis is that such CRISPR-edited "stealth" kidneys will be significantly less immunogenic, leading to fewer acute rejection episodes and reduced anti-graft antibody formation, thereby improving transplant success.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
90
The donor kidney is treated outside the body with CRISPR-Cas9 ribonucleoprotein complexes targeting the genes HLA-A, HLA-B, and CIITA. This genetic intervention knocks out HLA-A/B on donor cells and disables expression of HLA-DR, -DQ, -DP by disrupting CIITA (essential for class II antigen presentation). The goal is to create a transplanted organ with greatly reduced immunogenic surface proteins. (This is a one-time genetic manipulation applied to the donor organ prior to transplantation; no direct gene therapy is given to the patient's own cells.)
After gene editing, the donor kidney is implanted into the recipient in a surgical transplant procedure. Standard peri-operative care is provided. All patients will receive standard immunosuppressive therapy post-transplant (such as tacrolimus, mycophenolate, and prednisone, per center protocol) to prevent rejection, though the regimen may be tailored based on the edited graft's expected lower immunogenicity. Patients will be hospitalized for transplant and monitored closely during the immediate post-op period, then followed in clinic frequently for transplant aftercare.
Peking University Health Science Center (PKUHSC)
Beijing, Changping, China
RECRUITINGIncidence of Treatment-Related Serious Adverse Events
Number of participants who experience any serious adverse event (SAE) that is possibly related to the gene-edited transplant procedure within the first 12 months post-transplant.
Time frame: Day 0 to Day 365 post-transplant
Graft Survival at 6 Months
Proportion of transplanted gene-edited kidneys that remain viable and functional at 6 months post-transplant. Graft survival is defined as the kidney graft not being lost to rejection or other causes (i.e., the recipient is alive with a functioning transplant, not returning to chronic dialysis) Unit of Measure: Participants with functioning graft (n, %)
Time frame: 6 months
Acute Rejection Episodes
Incidence of acute rejection events within the first 12 months post-transplant. This will be measured as the number of episodes of biopsy-confirmed acute allograft rejection (acute T-cell mediated rejection or antibody-mediated rejection) per patient, and the proportion of patients who experience at least one rejection. Unit of Measure: Episodes per participant
Time frame: 12 months
Donor-Specific Antibody (DSA) Development
Number of participants who develop de-novo anti-donor HLA antibodies (MFI ≥1000). Time Frame: Baseline to Month 12 Unit of Measure: Participants with de-novo DSA (n, %)
Time frame: 12 months
Mean eGFR at Month 12
Average eGFR calculated by CKD-EPI at Month 12 ±7 days. Unit: mL/min/1.73 m² (mean ± SD)
Time frame: 12 months
Frequency of Donor-Reactive IFN-γ Producing T Cells (ELISPOT)
Spot-forming cells per 10⁶ PBMC in ELISPOT assay at Month 6 compared with baseline. Unit: Spot-forming cells/10⁶ PBMC (mean ± SD)
Time frame: 12 months
Percentage of HLA-A Alleles with Indel Mutation (NGS)
Indel frequency at HLA-A locus in pre-implant biopsy determined by next-gen sequencing.Unit: Percent alleles edited (%)
Time frame: 30 days
Overall Patient Survival at 12 Months
Participants alive at 12 months post-transplant.
Time frame: 12 months
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.