CareDx, Inc. (NASDAQ: CDNA) — The Transplant Company™, a precision medicine company focused on transplant patients, announced its participation at the American Transplant Congress (ATC) 2026. The event takes place June 20–24 in Boston, Massachusetts. The company presented data supporting AlloSure® as a clinical endpoint for risk assessment, treatment response, and long-term graft outcomes.

Real-world clinical use and scientific advancements involving AlloSure Kidney, AlloSure Plus, HistoMap Kidney, HeartCare (AlloMap Heart and AlloSure Heart), and AlloSure Lung were featured in more than 30 abstracts and 9 oral presentations. The data were generated from studies at over 110 transplant centers across the United States. The findings reflect the continued evolution of AlloSure dd-cfDNA from an emerging biomarker to a potential clinical endpoint.

Dr. Jeffrey Teuteberg, Chief Medical Officer of CareDx, stated that the data indicate a shift where AlloSure is being explored to evaluate treatment response, stratify risk, and predict graft outcomes. He noted that this has implications for patient management and clinical trial design. The company also presented work on spatial transcriptomics to provide insights into immune activation and injury.

Key Study Findings in Kidney Transplantation

Studies demonstrated the prognostic value of early AlloSure monitoring. Persistent elevation in the first four months after kidney transplantation was associated with higher rates of rejection, de novo DSA, eGFR decline, and graft loss at three years. Transient elevations that normalized showed outcomes comparable to consistently low levels.

In a study of tocilizumab for antibody-mediated rejection, AlloSure levels remained elevated over 12 months despite reductions in DSA and stabilization of eGFR. This correlated with persistent histologic AMR on follow-up biopsy. A multicenter analysis of more than 4,000 kidney transplant recipients found elevated AlloSure was independently associated with microvascular inflammation (MVI) phenotypes, including DSA-negative, C4d-negative MVI.

AlloSure Plus scores were significantly higher in biopsy-confirmed acute cellular rejection (ACR) and antibody-mediated rejection (AMR) compared to no rejection. The scores showed an AUROC of 0.79 for discriminating rejection.

Next-Generation Biomarker Discovery

HistoMap Kidney molecular analysis classified the majority of biopsies with isolated arteritis (v-lesions) as "No Rejection." This suggests that isolated arteritis may not represent active T-cell-mediated rejection. The integration of single-cell and spatial transcriptomics via ImmuneScape™ revealed distinct immune cell populations and spatial immune infiltration patterns associated with kidney allograft rejection.

Key Study Findings in Heart Transplantation

In heart transplantation, higher AlloMap scores were significantly associated with subsequent elevations in AlloSure Heart. The risk increased at gene expression profiling (GEP) scores ≥25. This supports AlloMap as an early indicator of immune activation that may precede graft injury detected by dd-cfDNA alone.

Patients initiated on mammalian target of rapamycin inhibitor (mTORi) showed increased evidence of molecular rejection as detected by HeartCare. The data suggest more frequent non-invasive monitoring may be warranted in this population.

New Study Finding in Multiorgan Transplantation

HeartCare was routinely incorporated in post-transplant follow-up for simultaneous heart-kidney transplant recipients. With consistent testing frequency, investigators demonstrated predictable patterns in molecular testing results.

CareDx Symposia

A panel of transplant nephrologists discussed the application of AlloSure Kidney and AlloSure Plus rejection risk assessment in clinical decision-making. The symposium featured data from the recently-published second manuscript of the Kidney Allograft Outcomes AlloSure (KOAR) registry.

CareDx, Inc. announced the publication of a new analysis from the Kidney Allograft Outcomes AlloSure Registry (KOAR) in the Journal of the American Society of Nephrology. The study establishes a link between elevations in its AlloSure Kidney donor-derived cell-free DNA (dd-cfDNA) test and increased risk of graft dysfunction and loss in kidney transplant recipients. This finding supports the role of AlloSure Kidney as a noninvasive tool for longitudinal risk stratification and clinical decision-making.

The second manuscript from KOAR evaluated the relationship between AlloSure Kidney dd-cfDNA and three-year kidney allograft outcomes in a multi-center cohort of 1,258 adult kidney transplant recipients across 56 U.S. centers. The study applied a multistate modeling framework to assess how longitudinal changes in AlloSure dd-cfDNA levels over time relate to subsequent allograft dysfunction and graft loss. During follow-up, approximately 36% of patients experienced dd-cfDNA elevation, transitioning from low to higher-risk states.

Key Findings from KOAR Analysis

The analysis demonstrated that transitions to elevated AlloSure levels were associated with significantly higher risks of allograft loss. The study also highlighted the ability of the test to detect subclinical injury prior to a measurable decline in estimated glomerular filtration rate (eGFR).

Additional findings include:

• Even a single elevation in AlloSure was associated with a measurable shift in clinical trajectory.
• Most AlloSure elevations occurred while kidney function remained preserved, demonstrating the ability to detect subclinical injury prior to measurable decline in eGFR.
• Patients with persistently low AlloSure levels experienced favorable outcomes, including low rates of rejection, dysfunction, and graft loss over three years.

Clinical Implications

"This analysis from the KOAR registry shows that elevations in dd-cfDNA are associated with meaningful differences in long-term allograft outcomes," said Jeffrey A. Klein, MD, Division of Nephrology, University of Kansas. "Importantly, we observed that many of these elevations occur while kidney function remains preserved, highlighting the potential for dd-cfDNA to provide earlier insight into allograft injury and help inform patient management."

Jonathan S. Bromberg, MD, PhD, Professor of Surgery at the University of Maryland School of Medicine, noted that the registry provides real-world evidence. "These findings suggest that tracking dd-cfDNA over time may offer a useful framework for risk stratification and longitudinal surveillance in kidney transplant recipients," he said.

Jeffrey Teuteberg, MD, Chief Medical Officer of CareDx, emphasized the biomarker's value. "These results from KOAR extend the growing body of evidence supporting AlloSure dd-cfDNA as a clinically meaningful biomarker in kidney transplantation," Teuteberg stated. "By enabling earlier identification of changes in allograft status, AlloSure may help clinicians assess risk over time and support more personalized patient management."