AlloSure for the Monitoring of Antibody Mediated Processes After Kidney Transplantation

Active, not recruiting

• Conditions: Kidney Transplant Failure and Rejection
• Interventions: Diagnostic Test: AlloSure ddcfDNA assay; Diagnostic Test: AlloMap assay; Diagnostic Test: Inflammatory Cytokines; Diagnostic Test: Immune Cell Phenotypes

• Registration Number: NCT04057742
• Lead Sponsor: University of Wisconsin, Madison

Brief Summary

This is a prospective cohort observational study to assess the role of AlloSure Donor Derived Cell Free DNA (ddcfDNA) assay in the monitoring of three high-risk groups of kidney transplant patients for antibody mediated processes.

* Group A. Thirty participants with a positive Virtual Cross-Match (VXM) at the time of transplant will be monitored for 12 months

* Group B. Similarly, 24 participants with dnDSA will undergo a SOC biopsy within approximately three months to determine the incidence of Active Antibody Mediated Rejection (AMR)

* Group C. 15 additional participants with the diagnosis of Chronic Active Antibody Mediated Rejection (cAMR) will undergo standard of care therapy and be monitored for treatment response with a follow-up biopsy at three months

Detailed Description

This is a prospective cohort observational study to assess the role of AlloSure Donor Derived Cell Free DNA (ddcfDNA) assay in the monitoring of three high-risk groups of patients for antibody mediated processes.

The AlloSure assay will be combined with the AlloMAP assay (PAXgene blood sample); which is the first in history FDA-cleared genomic solid organ transplantation rejection blood test (AlloMap). Immune cell phenotypes and inflammatory cytokines will be examined. The combination of the three assays will provide a comprehensive molecular diagnostic and prognostic approach to antibody-mediated processes after renal transplantation. Additionally, formalin fixed paraffin embedded (FFPE) samples from kidney biopsies for subjects in all groups will be used to validate the nCounter platform. 3 slides from each biopsy will be sent to CareDx to be examined on the nCounter system. Other routine clinical data will be examined and assessed for correlation with the nCounter results. This will include AlloSure, Molecular Microscope, eGFR, creatinine, DSA as well as other key data fields taken from the Electronic Medical Record (EMR).

AlloMap Kidney is a lab-developed test and will be provided by CareDx, Inc. located at Brisbane, CA, and is designed, manufactured and used within a single CareDx laboratory. AlloMap Kidney is currently provided as "For Research use only" test and results are not intended for clinical diagnosis or patient management for "KidneyCare", which is the AlloSure-Kidney and AlloMap-Kidney tests combined.

* Group A. Thirty participants with a positive VXM at the time of transplant will be monitored for 12 months and undergo protocol biopsies on months 3 and 12 to detect subclinical rejection. Participants may also undergo clinically indicated biopsies for suspicion of rejection. AlloSure, AlloMap, immune cell phenotypes, and inflammatory cytokines will be measured at baseline (within 48 hours of transplant), 3 weeks, 6 weeks, 3M (SOC biopsy), 6M, 12M (SOC biopsy) and additionally at the time of any indication biopsy (5-7 time points/patient). Subjects in this group will be monitored for 12 months.

* Group B. Similarly, 24 participants with dnDSA will undergo a SOC biopsy within approximately three months to determine the incidence of AMR. Immune cell phenotyping, AlloSure and AlloMap will be measured at the time of the SOC biopsy (1 timepoint/patient). This is a single-time point study, unless participants are diagnosed with AMR and require treatment. In this case, they would be enrolled in group C (see below).

* Group C. 15 additional participants with the diagnosis of cAMR will undergo standard of care therapy and be monitored for treatment response with a follow-up biopsy at three months. Immune cell phenotyping, AlloSure and AlloMap will be used at baseline (prior to index biopsy) and 3M (follow-up surveillance biopsy) (2 timepoints/patient). Participants in this group will be monitored per SOC for three months (time between the two biopsies).

For all three groups, history and physical, blood draws and urine sample collections are performed per SOC. The only addition is blood sample collection and additional urine collection at the indicated SOC timepoints for AlloSure, AlloMap, immune cell flow cytometry, RNA-signatures, and inflammatory cytokines. In addition, leftover pathology slides that are stored in the pathology department will be sent out to CareDx for the purposes of performing the NanoString analysis. The slides will be returned to the pathology department after the NanoString analysis is complete.

Study Timeline

• Study First Submitted: 2019-08-13
• Study First Submitted QC: 2019-08-13
• Study First Posted: 2019-08-15
• Study Start: 2019-10-07
• Status Verified: 2023-12
• Last Update Submitted: 2023-12-12
• Last Update Posted: 2023-12-13
• Primary Completion: 2024-08
• Study Completion: 2024-08

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: All
• Target Recruitment: 53

Inclusion Criteria

• Kidney transplant recipients (de novo or retransplant)
• Positive Virtual Crossmatch at transplant (Group A)
• Undergoing SOC biopsy for dnDSA (Group B)
• Proven cAMR (Group C)

Exclusion Criteria

• Multi-Visceral transplant
• Contraindication to renal biopsy

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Group A	Immune Cell Phenotypes	30 participants with a positive virtual crossmatch (VXM) at the time of transplant will be monitored for 12 months and undergo protocol biopsies on months 3 and 12 to detect subclinical rejection. Participants may also undergo clinically indicated biopsies for suspicion of rejection. AlloSure, AlloMap, immune cell phenotypes, and inflammatory cytokines will be measured at baseline (within 48 hours of transplant), 3 weeks, 6 weeks, 3 months (Standard of Care (SOC) biopsy), 6 months, 12 months (SOC biopsy), and additionally at the time of any indication biopsy (5-7 time points/participant). Participants in this group will be monitored for 12 months. Participants will be offered the option of donating either 22.5 mL of blood (Allosure+AlloMap+cytokines) or 52.5 mL of blood (Allosure+AlloMap+cytokines+immune cell phenotyping) at each visit. Participants may change their donation volume from 22.5 mL to 52.5 mL at any point during the study.
Group B	AlloMap assay	24 participants with De novo donor specific antibodies (dnDSA) will undergo a SOC biopsy within approximately three months to determine the incidence of Active Antibody Mediated Rejection (AMR). Immune cell phenotyping, AlloSure, and AlloMap will be measured at the time of the SOC biopsy (1 timepoint/patient). This is a single-time point study, unless participants are diagnosed with AMR and require treatment. In this case, they would be enrolled in group C (see below).
Group A	AlloSure ddcfDNA assay	30 participants with a positive virtual crossmatch (VXM) at the time of transplant will be monitored for 12 months and undergo protocol biopsies on months 3 and 12 to detect subclinical rejection. Participants may also undergo clinically indicated biopsies for suspicion of rejection. AlloSure, AlloMap, immune cell phenotypes, and inflammatory cytokines will be measured at baseline (within 48 hours of transplant), 3 weeks, 6 weeks, 3 months (Standard of Care (SOC) biopsy), 6 months, 12 months (SOC biopsy), and additionally at the time of any indication biopsy (5-7 time points/participant). Participants in this group will be monitored for 12 months. Participants will be offered the option of donating either 22.5 mL of blood (Allosure+AlloMap+cytokines) or 52.5 mL of blood (Allosure+AlloMap+cytokines+immune cell phenotyping) at each visit. Participants may change their donation volume from 22.5 mL to 52.5 mL at any point during the study.
Group A	AlloMap assay	30 participants with a positive virtual crossmatch (VXM) at the time of transplant will be monitored for 12 months and undergo protocol biopsies on months 3 and 12 to detect subclinical rejection. Participants may also undergo clinically indicated biopsies for suspicion of rejection. AlloSure, AlloMap, immune cell phenotypes, and inflammatory cytokines will be measured at baseline (within 48 hours of transplant), 3 weeks, 6 weeks, 3 months (Standard of Care (SOC) biopsy), 6 months, 12 months (SOC biopsy), and additionally at the time of any indication biopsy (5-7 time points/participant). Participants in this group will be monitored for 12 months. Participants will be offered the option of donating either 22.5 mL of blood (Allosure+AlloMap+cytokines) or 52.5 mL of blood (Allosure+AlloMap+cytokines+immune cell phenotyping) at each visit. Participants may change their donation volume from 22.5 mL to 52.5 mL at any point during the study.
Group C	AlloMap assay	15 additional participants with the diagnosis of Chronic Active Antibody Mediated Rejection (cAMR) will undergo standard of care therapy and be monitored for treatment response with a follow-up biopsy at three months. Immune cell phenotyping, AlloSure, and AlloMap will be used at baseline (prior to index biopsy) and 3 month (follow-up surveillance biopsy) (2 timepoints/participant). Participants in this group will be monitored per SOC for three months (time between the two biopsies).
Group A	Inflammatory Cytokines	30 participants with a positive virtual crossmatch (VXM) at the time of transplant will be monitored for 12 months and undergo protocol biopsies on months 3 and 12 to detect subclinical rejection. Participants may also undergo clinically indicated biopsies for suspicion of rejection. AlloSure, AlloMap, immune cell phenotypes, and inflammatory cytokines will be measured at baseline (within 48 hours of transplant), 3 weeks, 6 weeks, 3 months (Standard of Care (SOC) biopsy), 6 months, 12 months (SOC biopsy), and additionally at the time of any indication biopsy (5-7 time points/participant). Participants in this group will be monitored for 12 months. Participants will be offered the option of donating either 22.5 mL of blood (Allosure+AlloMap+cytokines) or 52.5 mL of blood (Allosure+AlloMap+cytokines+immune cell phenotyping) at each visit. Participants may change their donation volume from 22.5 mL to 52.5 mL at any point during the study.
Group B	AlloSure ddcfDNA assay	24 participants with De novo donor specific antibodies (dnDSA) will undergo a SOC biopsy within approximately three months to determine the incidence of Active Antibody Mediated Rejection (AMR). Immune cell phenotyping, AlloSure, and AlloMap will be measured at the time of the SOC biopsy (1 timepoint/patient). This is a single-time point study, unless participants are diagnosed with AMR and require treatment. In this case, they would be enrolled in group C (see below).
Group C	AlloSure ddcfDNA assay	15 additional participants with the diagnosis of Chronic Active Antibody Mediated Rejection (cAMR) will undergo standard of care therapy and be monitored for treatment response with a follow-up biopsy at three months. Immune cell phenotyping, AlloSure, and AlloMap will be used at baseline (prior to index biopsy) and 3 month (follow-up surveillance biopsy) (2 timepoints/participant). Participants in this group will be monitored per SOC for three months (time between the two biopsies).
Group B	Immune Cell Phenotypes	24 participants with De novo donor specific antibodies (dnDSA) will undergo a SOC biopsy within approximately three months to determine the incidence of Active Antibody Mediated Rejection (AMR). Immune cell phenotyping, AlloSure, and AlloMap will be measured at the time of the SOC biopsy (1 timepoint/patient). This is a single-time point study, unless participants are diagnosed with AMR and require treatment. In this case, they would be enrolled in group C (see below).
Group C	Immune Cell Phenotypes	15 additional participants with the diagnosis of Chronic Active Antibody Mediated Rejection (cAMR) will undergo standard of care therapy and be monitored for treatment response with a follow-up biopsy at three months. Immune cell phenotyping, AlloSure, and AlloMap will be used at baseline (prior to index biopsy) and 3 month (follow-up surveillance biopsy) (2 timepoints/participant). Participants in this group will be monitored per SOC for three months (time between the two biopsies).

Primary Outcome Measures

Name	Time	Method
Incidence of Biopsy Confirmed AMR	up to 12 months post-transplant	To determine whether AlloSure, immune cell phenotypes, and inflammatory cytokines predict the incidence of AMR, the outcome measure will be incidence of biopsy confirmed AMR. For participants with a positive virtual crossmatch (group A), protocol biopsies are performed at 3 and 12 months posttransplant. For participants with De novo donor specific antibodies (dnDSA) (group B), protocol biopsies are performed within 3 months.

Secondary Outcome Measures

Name	Time	Method
Renal Allograft Function: Estimated Glomerular Filtration Rate (eGFR)	up to 3 months following initial diagnosis of cAMR	To determine whether AlloSure predicts the course of disease and/or response to treatment in participants with cAMR, renal allograft function will be assessed by measuring eGFR at baseline (index biopsy) and up to 3 months following SOC biopsy-proven cAMR.
Number of Genes Upregulated for BK Virus as determined by Nanostring nCounter	experiment performed within 7 days of receiving sample	Genes within the Nanostring panel are associated with BK infection, will be examined with FFPE tissue taken from participants who had clinical BK infection.
Renal Allograft Function: Concentration of Serum Creatinine (sCr)	up to 3 months following initial diagnosis of cAMR	To determine whether AlloSure predicts the course of disease and/or response to treatment in participants with cAMR, renal allograft function will be assessed by measuring sCR at baseline (index biopsy) and up to 3 months following SOC biopsy-proven cAMR.
Percent of Biopsy Samples Measured on Nanostring nCounter That Validate Clinical Outcomes	experiment performed within 7 days of receiving sample	Validation of Nanostring nCounter platform using FFPE kidney biopsy tissue to assess tissue GEP in the context of Allograft Rejection in Groups A, B, and C.; GEP will be measured on the FFPE tissue to assess the patterns associated with allograft rejection. Samples will be retrospectively analysed from historic kidney biopsies performed, where the clinical diagnosis and outcome is known. Results will be compared to the gold standard of histopathology analysis.
Number of Genes Upregulated in Allograft Rejection	experiment performed within 7 days of receiving sample	GEP analysis of FFPE tissue will be analysed to identify what pattern of genes are involved with different types of rejection and see whether the platform matches what has already been published in the literature.
Banff Pathology	up to 3 months following initial diagnosis of cAMR	To determine whether AlloSure and immune cell phenotyping predict the course of disease and/or response to treatment in participants with cAMR (Group C) the Banff pathology will be assessed.
Renal Allograft Function: Urinary Protein to Creatinine Ratio (UPC)	up to 3 months following initial diagnosis of cAMR	To determine whether AlloSure predicts the course of disease and/or response to treatment in participants with cAMR, renal allograft function will be assessed by measuring UPC at baseline (index biopsy) and up to 3 months following SOC biopsy-proven cAMR.

Trial Locations

Locations (1)

University of Wisconsin - Madison; 🇺🇸 Madison, Wisconsin, United States