CareDx Announces Landmark KOAR Study Published in the American Journal of Transplantation

August 06, 2025 at 12:56 PM EDT

KOAR, the Largest Prospective Study of Its Kind, Demonstrates Clinical Utility of AlloSure® in Kidney Transplant Surveillance

AlloSure Kidney dd-cfDNA Elevation Strongly Predicts Rejection and Improves Biopsy Yield

CareDx, Inc. (Nasdaq: CDNA), — The Transplant Company™ — a leading precision medicine company focused on the discovery, development, and commercialization of clinically differentiated, high-value healthcare solutions for transplant patients and caregivers, today announced the publication of the Kidney Allograft Outcomes AlloSure Registry (KOAR) study in the American Journal of Transplantation. The landmark prospective study demonstrates the clinical utility of AlloSure® donor-derived cell-free DNA (dd-cfDNA) in improving rejection detection and guiding biopsy decisions in kidney transplant recipients.

The KOAR study enrolled 1,743 patients across 56 U.S. transplant centers to evaluate the clinical utility of a dd-cfDNA surveillance protocol based on the DART study, which prescribed seven tests in year one and four annually in years two and three. A total of 18,584 AlloSure tests were obtained from the overall cohort.

“The scale and clarity of KOAR make it a landmark,” said Daniel C. Brennan, MD, Professor of Medicine at Johns Hopkins, author of the publication, and the senior author of the primary DART publication. “In fact, it shows that dd-cfDNA should be considered the first-line test even before DSA. It’s arguably the most powerful biomarker we have in kidney transplantation today.”

“KOAR confirms that dd-cfDNA is a clinically actionable tool that enhances how we detect and manage rejection,” said Jonathan S. Bromberg, MD, PhD, Professor of Surgery at the University of Maryland, lead author of the publication, and a key author on the DART publications. “Importantly, it helps clinicians tailor care based on risk.”

Key findings include:

Elevated AlloSure was associated with a 6-fold increase in rejection yield in surveillance biopsies (39% vs. 7%, p<0.001) and a 4-fold increase in for-cause biopsies (47% vs. 12%, p<0.001).
AlloSure elevations were detectable up to four months before ABMR and one month before TCMR, supporting its role in early detection and longitudinal monitoring.
In post-biopsy monitoring, AlloSure levels declined significantly following treatment, while serum creatinine remained unchanged, reinforcing AlloSure’s role in assessing treatment response.

The study also demonstrated that dd-cfDNA levels correlate with rejection severity, with higher levels associated with ABMR and mixed rejection, and lower levels linked to borderline or TCMR 1A. This stratification capability positions AlloSure as a critical tool for tailoring immunosuppression and biopsy decisions based on individual patient risk.

“The KOAR study provides compelling evidence that dd-cfDNA can optimize biopsy utilization and improve clinical decision-making in kidney transplant care,” said Robert Woodward, Chief Scientific Officer of CareDx. “AlloSure empowers physicians to detect rejection earlier and intervene more precisely, to achieve the ultimate goal of improving long-term graft survival.”

The full publication is available online at: https://www.amjtransplant.org/article/S1600-6135(25)02875-8/fulltext

About CareDx

CareDx, Inc., headquartered in Brisbane, California, is a precision medicine company focused on the discovery, development, and commercialization of clinically differentiated, high-value healthcare solutions for transplant patients and caregivers. For more information, visit www.caredx.com.

Forward Looking Statements

This press release includes forward-looking statements related to CareDx, Inc., including statements regarding the potential benefits and results that may be achieved with AlloSure Kidney. These forward-looking statements are based upon information that is currently available to CareDx and its current expectations, speak only as of the date hereof, and are subject to risks and uncertainties that could cause actual results to differ materially from those projected, including risks that CareDx does not realize the expected benefits of AlloSure Kidney; risks that the findings in the KAOR study supporting the data may be inaccurate, general economic and market factors; risks that the findings in the studies supporting the data may be inaccurate, general economic and market factors, and other risks discussed in CareDx’s filings with the Securities and Exchange Commission (the “SEC”), including, but not limited to, the Annual Report on Form 10-K for the fiscal year ended December 31, 2024 filed by CareDx with the SEC on February 28, 2025, and other reports that CareDx has filed with the SEC. Any of these may cause CareDx’s actual results, performance, or achievements to differ materially and adversely from those anticipated or implied by CareDx’s forward-looking statements. You are cautioned not to place undue reliance on these forward-looking statements. CareDx expressly disclaims any obligation, except as required by law, or undertaking to update or revise any such forward-looking statements, whether as a result of new information, future events or otherwise.