NCT Number: NCT07718308
This multicenter, prospective, single-arm exploratory study evaluates the efficacy and safety of a novel sequential regimen for chronic active antibody-mediated rejection (caABMR) in kidney transplant recipients: single-dose CD38 monoclonal antibody (1800 mg subcutaneous) induction to deplete plasma cells and NK cells, followed by long-term maintenance with azathioprine (replacing mycophenolate mofetil) plus standard triple immunosuppression (steroid + calcineurin inhibitor). The regimen aims to control DSA-driven injury, stabilize or improve graft function (primary: eGFR decline slope), reduce DSA, improve pathology (Banff 2022), and minimize infection/nephrotoxicity risks associated with intensified or prolonged biologic therapy. Twenty patients across 6 Chinese transplant centers will be enrolled. CD38 mAb, azathioprine, key monitoring tests (HLA antibody, pharmacogenomics, immune profiling) are provided free by the study team (~40,000 RMB per patient). Ethics approved; informed consent obtained.
Trial opening soon.
Get Notified18 year and older
All sexes
Interventional
Not applicable
Background: caABMR is the leading cause of late kidney allograft loss. Current therapies (plasmapheresis, IVIG, rituximab, bortezomib, long-term CD38 mAb) have limited efficacy, high recurrence, significant side effects, and high cost with no approved standard.
Rationale: CD38 mAb depletes antibody-producing plasma cells and pathogenic NK cells, rapidly lowering DSA and micro vascular inflammation. However, long-term monotherapy is costly and may increase infection risk. This study uses single induction dose + switch to azathioprine (safe, inexpensive, long-used in transplantation, suppresses NK activity) for durable, affordable maintenance. TPMT/NUDT15 genotyping guides personalized AZA dosing; serial NK cell monitoring targets <20/μL.
Design: Multicenter (6 centers), prospective, open-label, single-arm, exploratory (N=20).
Intervention: Baseline: CD38 mAb 1800 mg SC x1 + immediate switch MMF→AZA (dose per genotype: normal metabolizer 2-3 mg/kg/d; intermediate 0.6-2.4 mg/kg/d). Maintain triple IS (steroid + AZA + Tac target 5-7 ng/mL or CsA 150-250 ng/mL).
Healthy volunteers accepted: No
Only the study team can determine whether someone qualifies for participation.
Inclusion criteria
Exclusion criteria
Single 1800 mg subcutaneous injection at baseline to induce rapid depletion of plasma cells (source of DSA) and NK cells (key effectors of microvascular injury in caABMR). Marketed anti-CD38 mAb (off-label use in this indication).
Other names: CD38 mAb, anti-CD38 monoclonal antibody
Oral azathioprine maintenance (replaces mycophenolate), individualized starting dose 2.0-3.0 mg/kg/day (normal TPMT/NUDT15 metabolizer) or 30-80% reduced (intermediate metabolizer), titrated per serial NK cell counts and hematologic tolerance. Long-term NK suppression to maintain immune balance and protect graft.
Other names: AZA, Imuran (or generic)
Continued per local practice with protocol targets
Time frame: Baseline through Week 28, planned assessments at weeks 0, 4, 8, 12, 16, 20, 24, 28
The primary efficacy endpoint is the slope of eGFR decline over 28 weeks, calculated from serial serum creatinine measurements (every 4 weeks) using the 2021 CKD-EPI equation. Serum creatinine is measured by enzymatic method or isotope dilution mass spectrometry. Slope is estimated via linear mixed-effects model or ordinary least-squares regression per patient, then summarized. Negative slope indicates ongoing graft loss; less negative or positive slope indicates stabilization or improvement of renal function after treatment.
Time frame: Baseline, Week 1, Week 2, Week 4, Week 8, Week 12, Week 16, Week 20, Week 24, Week 28
Quantitative detection of lymphocyte subpopulations (NK, T, B cells) in peripheral blood via flow cytometry; evaluate the absolute count and relative percentage changes at each follow-up time point.
Time frame: Baseline, Week 1, Week 2, Week 4, Week 8, Week 12, Week 16, Week 20, Week 24, Week 28
Estimated glomerular filtration rate (eGFR) is calculated by the CKD-EPI 2021 formula. Both absolute value and relative percentage change of eGFR will be evaluated at all scheduled follow-up visits.
Time frame: Baseline and Week 28
Urine protein-to-creatinine ratio (UPCR) measured in mg/g or mg/mmol. Urine protein is tested via pyrogallol red molybdate method, and creatinine is detected using sarcosine oxidase assay. The relative percentage change of UPCR is used to evaluate renal therapeutic efficacy.
Time frame: Baseline, Week 8, Week 28
Donor-specific antibody MFI is detected via Luminex single-antigen bead assay. Relative percentage change from baseline will be calculated to evaluate the reduction of alloantibody levels.
Time frame: Baseline, Week 28
Banff 2022 renal allograft pathology scoring system is applied for the interpretation of protocol kidney biopsy specimens. The scores include microcirculation inflammation, tubulitis, interstitial inflammation, chronic glomerulopathy, transplant glomerulitis and chronic arteriopathy. The pathological scores are recorded at screening baseline and week-28 follow-up biopsy. The variation of each individual Banff lesion score between two time-points will be analyzed. Higher Banff lesion scores represent more severe renal allograft injury.
Time frame: Through Week 28
Cumulative incidence (%) of biopsy-proven acute rejection, including T cell-mediated rejection (TCMR), antibody-mediated rejection (AMR), and mixed rejection, diagnosed according to Banff 2022 classification criteria.
Time frame: Week 28
The proportion of subjects who remain alive without all-cause mortality at the designated follow-up time point
Time frame: Week 28
Percentage of participants with functioning renal allograft, defined as no return to maintenance dialysis and no secondary kidney retransplantation
Time frame: Through Week 28
Cases of BK virus infection are categorized as BKV viruria (>10³ copies/mL), BKV viremia (≥10⁴ copies/mL), or biopsy-confirmed BKV nephropathy identified by renal histology combined with SV40 IHC or ISH staining. Cumulative incidence percentage will be calculated for each category.
Time frame: Through Week 28
Cytomegalovirus infection is defined as detectable CMV DNA ≥10³ copies/mL quantified via quantitative PCR (qPCR). Cumulative incidence percentage of affected subjects will be summarized.
Time frame: Through Week 28
Neutropenia is stratified by absolute neutrophil count (ANC): mild ANC <1.5×10⁹/L, moderate ANC <1.0×10⁹/L, severe ANC <0.5×10⁹/L. Cumulative incidence percentage will be stratified by severity grades defined per NCI CTCAE or study protocol criteria.
Time frame: Through Week 28
All infusion-related adverse events during the whole follow-up period will be recorded, including fever, chills, hypotension, dyspnea and other infusion-associated manifestations.
Time frame: Through Week 28
The type, severity, relation to study medication and occurrence frequency of all adverse events and serious adverse events will be collected, according to CTCAE common terminology criteria.
Time frame: Through Week 28
Liver function indexes including alanine transaminase, aspartate transaminase, total bilirubin will be tested regularly. Liver function abnormality is defined as laboratory elevation exceeding 3-fold upper limit of normal range.
Time frame: Through Week 28
All hospitalization events for any reason during follow-up will be documented, including the admission time, diagnosis and length of hospital stay.
Contact information is provided by the study sponsor or research team.
wujianyong
Other
A Multicenter Exploratory Clinical Study of Targeted NK Cell Inhibition for Transplant Kidney Chronic Active Antibody-Mediated Rejection (caABMR): Single Induction With CD38 Monoclonal Antibody Followed by Sequential Maintenance With Azathioprine
Acronym: CAZA
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View the official ClinicalTrials.gov record (opens in a new tab)This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.
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