Yes to FDA Regulation of LDTs, But We Need a New Framework, Says David Spetzler

David Spetzler, CSO, Caris Life Sciences


Listen 0:00 Molecular profiles of over 80000 cancer patients (5:30)

Listen 5:30 Yes to more regulation of molecular tests (6:54)

Listen 12:23 The right regulatory framework still missing (5:13)

Listen 17:36 Does Caris offer a product or a service? (3:25)

Listen 21:03 A new kind of liquid biopsy based on exosomes (4:20)

Listen 25:22 What does Caris look like in five years? (3:25)

We set up an interview with David Spetzler, the CSO of Caris Life Sciences, to hear about some promising new liquid biopsy tests they are developing. And we do that in today’s show. But first, the interview takes a turn toward the regulation of molecular tests. Spetzler says that Caris is already doing as many quality certifications as possible short of FDA oversight.

“We are actually quite favorable to increases in regulation,” he says, “We think there’s a lot of bad science being done, quite honestly, because it’s expensive to take the additional steps to insure that high quality work is being performed. And we’re doing those steps, so we might as well get credit for it.”

At the same time, Spetzler says that an appropriate framework to evaluate the utility of molecular profiling is missing. Traditional blind trials don’t work for molecular tests, he warns. The studies must be more longitudinal and be focused on more than just one biomarker at a time. Caris is currently running a study that “backs away from individual biomarker validation and focuses on process validation to identify underlying treatment opportunities for patients with particular molecular profiles.”

We do get to a discussion of Caris’ upcoming liquid biopsy tests, such as one that screens for breast cancer. This past year we’ve seen an explosion in the industry of these new non-invasive, blood-based tests. But whereas most companies are looking at cell free DNA (cfDNA) or circulating tumor cells (CTCs), Caris has come up with a novel platform using exosomes. These are small vesicles that handle intracellular communication and are not only present in all biological fluids but much more ubiquitous than cfDNA or CTCs.