Insight Molecular Diagnostics (iMDx) announced positive results from a head-to-head comparison study demonstrating that its digital PCR-based transplant rejection testing platform performs equivalently to next-generation sequencing (NGS) methods in measuring donor-derived cell-free DNA (dd-cfDNA), a key biomarker for assessing transplant rejection risk.
The study, conducted by University Hospital Heidelberg in Germany, evaluated 96 kidney transplant recipients undergoing for-cause biopsies and represents the first direct comparison of two commercially available dd-cfDNA test kits based on single nucleotide polymorphisms (SNPs). Results showed equivalent measurements between iMDx's GraftAssureIQ platform and NGS-based testing methods.
Study Design and Methodology
The comparative analysis examined iMDx's digital PCR technology against NGS platforms, with both methods utilizing SNPs to distinguish between donor and recipient DNA. Unlike sequencing-based approaches, digital PCR does not sequence DNA but instead precisely quantifies specific DNA targets in a sample.
GraftAssureIQ enables both absolute and relative quantification of dd-cfDNA using validated patient-specific variants. The study results showed tight correlation across all biopsy-proven pathology categories according to BANFF 2022 criteria, confirming what researchers describe as clinical interchangeability between the two methods.
"This first of its kind, head-to-head comparison demonstrates that digital PCR and NGS platforms deliver equivalent dd-cfDNA results in kidney transplant recipients," said Dr. Ekkehard Schuetz, iMDx Chief Science Officer. "We believe the tight correlation across all biopsy-proven pathology categories (BANFF 2022) confirms the clinical interchangeability of both methods."
Digital PCR Advantages
While both approaches aligned clinically, the study revealed that digital PCR demonstrated improved analytical sensitivity compared to NGS methods. This enhanced sensitivity suggests potential advantages in detecting dd-cfDNA in low quantities, which could be clinically significant for early detection of transplant complications.
The findings support the reliability of both platforms and reinforce the role of dd-cfDNA testing in routine transplant care, according to the study authors.
Commercial Implications
The positive data supports iMDx's preparation for commercial launch following expected regulatory approval next year. CEO Josh Riggs emphasized the value of head-to-head comparative data for market preparation.
"Head-to-head data like this is highly valuable as we prepare for commercial launch following expected regulatory approval next year," Riggs said. "The study results give us confidence that our platform performs on par with NGS-based options currently on the market."
The company is targeting the estimated $1 billion transplant rejection testing market with its diagnostic platform. iMDx is currently executing key steps necessary to transition from product development to commercialization in 2025.
Product Development Pipeline
iMDx's transplant diagnostics portfolio under the GraftAssure brand includes three main components:
- GraftAssureCore: The company's lab-developed test currently reimbursed by CMS and performed at its CLIA-certified laboratory in Nashville
- GraftAssureIQ: A research-use-only kit for non-clinical applications, which was evaluated in the current study
- GraftAssureDx: An in vitro diagnostic kit in development for clinical decision-making, which the company intends to submit for FDA authorization
The GraftAssureIQ platform studied in this research is clearly labeled for research use only and may not be used to support clinical treatment decisions. The company is concurrently developing GraftAssureDx for regulatory submission and clinical use.
Conference Presentations and Industry Engagement
Initial data from the study was presented at the European Renal Association 2025 conference in Vienna, Austria, from June 4-7, 2025. Extended data will be presented in a poster abstract at the upcoming European Society of Organ Transplantation Congress in London from June 29 through July 2.
iMDx will exhibit at ESOT throughout the conference duration, with attendees invited to visit booth D46 to learn about GraftAssureIQ and collaboration opportunities for transplant centers engaged in research and development.
The company also plans to host a Key Opinion Leader webinar featuring Dr. Anthony J. Langone of Vanderbilt University Medical Center, who serves as the national principal investigator for iMDx's ongoing kidney transplant monitoring trial. Registration details will be provided as part of the company's Q2 2025 earnings announcement.
