April 20, 2015
By Riley McDermid, BioSpace.com Breaking News Sr. Editor
Molecular diagnostics company CareDx is developing a cell-free DNA (cfDNA) blood test that can help transplant patients better gauge their overall health and progress as opposed to the traditional biopsies usually performed—and hopes to have a workable data from lab test by the end of 2015, James Yee, chief medical officer at CareDx, told BioSpace on Monday.
“Our evolving evidence indicates that cell-free DNA (cfDNA) can be further developed as simple and safe blood test that has the potential to better guide the care of transplant patients who need to be monitored over their lifetime,” Yee told BioSpace.
Brisbane, Calif.-based CareDx focuses on the discovery, development and commercialization of clinically differentiated, high-value, non-invasive diagnostic surveillance solutions for transplant recipients. The company has already commercialized AlloMap, a gene expression test that aids clinicians in identifying heart transplant recipients with stable graft function who have a low probability of moderate/severe acute cellular rejection.
Yee told BioSpace a new technology would be helpful for a patient population already taxed by lengthy procedures.“The current reference surveillance method for rejection is an invasive heart biopsy procedure. While biopsies have been considered the historic standard for heart transplant surveillance, they carry limitations of accuracy of interpretation and since the procedure can cause scarring and other cumulative risk of injury at the site of catheter insertion, as well as at the site of biopsy within the heart chamber, biopsies are not feasible for frequent use and long-term surveillance,” he said.
“Due to these and other limitations, biopsies are not frequently used by clinicians to tailor the use of immunosuppressants,” he added. “Further, because repeated biopsies incur cumulative risk and trauma to the recipient, the frequency of biopsy surveillance after one year has been low. New tools are needed to enhance non-invasive surveillance and decrease risk.”
The analyses of blood samples from a subset of patients from the multicenter Cardiac Allograft Rejection Gene expression Observational study II (CARGO II) heart transplant observational study represent the first time that researchers have measured both cfDNA and gene expression profiles (AlloMap) in blood samples taken from the same patients. Maria G. Crespo-Leiro, a cardiologist from Hospital Universitario A Coruna in Spain, presented the results last week at the 35th Annual Meeting and Scientific Sessions of the International Society for Heart and Lung Transplantation (ISHLT) held in Nice, France.
Yee said the release of that data has now added at least some structure to how CareDx will be approaching testing, and eventually debuting, its new technology.
“From a commercial perspective, we will develop cfDNA in heart transplant and in kidney transplant as CLIA-certified lab tests, and expect to achieve that status at the end of 2015,” he told BioSpace. “Heart transplant cfDNA results are available to patients through an ongoing study being conducted by CareDx named D-OAR which is a sub study of an outcomes AlloMap registry, named OAR. CareDx also has further samples and data for the CARGO II study repository to further explore in the near term future.”
Yee said that the company and its research team will initially focus on the heart and kidneys but could expand to other organs once it sees the positive data it needs to proceed.
We are focused on making proof-of-concept in heart first; then we are going to the biggest opportunity--which is kidney surveillance--then moving into other organs. But this initial data in heart transplant recipients is very encouraging,” he said. More data will be unveiled at the American Transplant Congress in Philadelphia in May, said Yee.
“In general, we continue to make significant progress in developing our pipeline of cfDNA testing for heart and kidney transplant patients,” said Yee. “We have structured our development trial program along three elements: first is analytical validity, followed by clinical validity, then clinical utility.”
