Trifecta-Heart cfDNA-MMDx Study

Study Overview
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Brief Summary
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Demonstrate the relationship between DD-cfDNA levels and HLA antibodies in blood transplant recipient and the Molecular Microscope® (MMDx) Diagnostic System results in indication and protocol biopsies from heart transplants.

Detailed Description
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The current standard for assessment of rejection in heart transplants is an endomyocardial biopsy (EMB) interpreted by histology according to ISHLT guidelines. This has considerable error rates, many due to the high disagreement among pathologists in assessing lesions and diagnoses. To address the unmet need for precision and accuracy, the Alberta Transplant Applied Genomics Centre (ATAGC, University of Alberta) has developed a new diagnostic system - the Molecular Microscope® Diagnostic System (MMDx), which uses microarrays to define the global gene expression features of rejection and injury. Now a new screening test is being introduced: the monitoring of donor-derived cell-free DNA (DD-cfDNA) released in the blood by the heart during rejection. The Natera Inc DD-cfDNA Prospera® test is based on the massively multiplex polymerase chain reaction that targets 13,392 single nucleotide polymorphisms and targeted sequences are quantified by Next Generation Sequencing. The Prospera® test has been done on kidney transplant recipients and detected active rejection and differentiated it from borderline rejection and no rejection. However, Prospera® test was not examined (the DD-cfDNA results) in heart transplant recipients. DD-cf-DNA test for heart transplants must now be calibrated against MMDx that is based on global gene expression, the new standard for biopsy interpretation. The present study will calibrate centrally measured (Natera Inc) DD-cfDNA levels obtained at the time of an indication or protocol biopsy against the MMDx measurements of T cell-mediated rejection (TCMR), antibody-mediated rejection (ABMR) and early and late tissue injury. The present study will compare DD-cfDNA and MMDx in 300 prospectively collected biopsies for clinical indications and protocol, and accompanying 600 blood samples, to calibrate the DD-cfDNA (Natera Inc.) levels against the MMDx biopsy diagnoses of TCMR, ABMR (and its stages), and acute (early) and chronic (late) injury, , as well as central assessment of HLA antibody (One Lambda) in 300 blood samples, interpreted centrally as donor specific antibody (DSA) based on the tissue typing results. Due to a considerable interest from participation centers, we extend this study to 700 biopsies and corresponding blood samples. This study is an extension of the INTERHEART ClinicalTrials.gov Identifier: NCT02670408

Official Title
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Trifecta-Heart cfDNA-MMDX Study: Comparing the DD-cfDNA Test to MMDx Microarray Test and Central HLA Antibody Test

Conditions
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Heart Transplant Rejection

Intervention / Treatment
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* Diagnostic Test: MMDx diagnostic test
* Diagnostic Test: Prospera
* Diagnostic Test: HLA antibody


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All heart transplant recipients undergoing a biopsy for clinical indications and protocol biopsies, as determined by their physician or surgeon, will be eligible to enroll in the study. Patients are enrolled based on standard of care biopsies, including surveillance biopsies in high-risk patients, with informed consent. Exclusion Criteria: Patients will be excluded from the study if they decline participation Are unable to give informed consent. Recipients of multiple organs.
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Heart transplant protocol and for cause biopsies<br>The study population includes patients with a functioning heart transplant undergoing a biopsy for clinical indications as standard of care, or protocol biopsies of heart in high-risk patients, or follow-up after treatment. | Diagnostic Test: MMDx diagnostic test<br>* Microarray test of gene expression in heart biopsies<br>Diagnostic Test: Prospera<br>* Donor derived cell-free DNA in patient blood<br>Diagnostic Test: HLA antibody<br>* Centralized measurement of HLA antibodies in patient blood<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Calibration of Prospera test for T cell-mediated rejection | Set DD-cfDNA test cut-off values against the probability of T cell-mediated rejection in the biopsy as reported by MMDx. Calibration of DD-cfDNA test cut-off values against the probability of T cell-mediated rejection in the biopsy as reported by MMDx. | 18 months | 
| Calibration of Prospera test for antibody-mediated rejection | Set DD-cfDNA test cut-off values against the probability of antibody-mediated rejection in the biopsy as reported by MMDx. | 18 months | 
| Calibration of Prospera test for heart injury | Set DD-cfDNA test cut-off values against the probability of acute and chronic heart injury in the biopsy as reported by MMDx. | 18 month | 
| Report calibrated Prospera test results for rejection | Obtain clinicians feedback | 6 months | 
| Report calibrated Prospera test results for heart injury | Obtain clinicians feedback | 6 month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Determine if Prospera blood test can replace heart biopsy test | Obtain clinicians feedback | 6 month | 
| Determine if Prospera blood test can replace follow up heart biopsy | Determine whether resolution of DD-cfDNA after treatment can monitor response to therapy and avoid follow-up biopsies | 6 month | 
| Assessment of donor-specific antibody status | Report and compare the DSA status based on centralized and local HLA antibody measurement. | 6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Donor derived cfDNA, gene expression, heart transplant biopsy