We also look at sample types—is whole blood, sputum, or plasma of interest? What samples are people working with? From there, we can say what the matrix is—the number of samples they’re going to process, the cost of running the samples, the reimbursement rate. At the end of the day, is it cost-efficient for a laboratory to take on this assay? This is the balance we’re trying to achieve with our R&D investment along with our overall investment in technology.
What do you suggest when reference standards for quality validations for LDTs are limited or nonexistent?
Steve Swartzell: Getting samples and controls for esoteric tests can be a challenge. Tickborne illnesses come to mind—there aren’t many choices for controls right now. There are companies that will start offering controls and calibrators for emerging diseases and conditions as they become more prevalent. In the meantime, many labs will culture their own for the test they’re trying to develop. There are places like ATCC [American Type Culture Collection] where you can get samples and spike it into the sample type you’re validating. It can be a difficult landscape to navigate.
Scott, the question of whether to send out tests or develop testing in-house is a golden oldie. The send-out can be expensive and time-consuming, but sometimes it’s appropriate for a given test.
Scott Johnston: Yes. It comes down to what resources the lab has. If the lab says, “We can take this in-house and we have enough samples that we want to process them,” then it makes sense. If the volumes are small and turnaround times are not a big issue, sending it out is probably the way to go. My hat’s off to my colleagues in reference labs and how quickly they can turn things around. But there’s an associated cost. If you look at the cost per data point, it’s probably more economical to internalize some tests if possible.
I’m struck by how many academic institutions now have testing networks that dominate large geographic areas. The University of Alabama at Birmingham, IU Health in Indiana, and Geisinger come to mind. Are LDTs attractive to large integrated delivery networks?
Scott Johnston: Yes. Small, medium, and large laboratories tend to look at similar types of diseases. Large networks like the ones you mentioned have figured out a way to optimize their testing capabilities. UAB in particular across that geography is much more efficient for that health network. But that doesn’t preclude the small lab. Small and regional labs don’t want to spend $150 for one data point when they could bring it in for $25 or $30. That makes sense to them.
How can ELITech and the ELITech molecular diagnostics group help a laboratory with LDT development? Tell us more about your large portfolio of ASR and RUO assays and the two validated IVD assays.
Scott Johnston: ASRs come in a specific configuration, and the government defines how to do the validations. The research-use-only assay is a CGMP [current good manufacturing practice] product, but it’s not configured in the same way as an ASR. It allows more flexibility. You have to do more upstream validation work to get the design of the study done and then push it forward. We see many folks who are interested in RUOs, but for the sake of overall validation purposes, an ASR is a little easier for them.
Steve, we all are exposed to the staffing shortages in laboratories and the retirements of senior laboratory scientists and others, but there’s still enough value in LDTs for many labs to pursue them. You needn’t be a 30-year MD/PhD—you can do this more readily than people in labs might imagine. Can you speak to that?
Steve Swartzell: Once the tests are validated, many labs will get it to a place where it is relatively simple to use, especially if you have a system that can do a full sample-to-result. Automated systems are becoming more prevalent and the use of LDTs has come along with those systems.
Scott, we would not have fared as well in the pandemic were it not for the vast number of LDTs that laboratories developed to deal with the testing load. Do you agree?
Scott Johnston: Yes. The speed with which labs adapted was phenomenal. It also instilled a newfound focus on molecular testing. The confidence in these tests and the knowledge around their use are much greater post-pandemic.
As we talk about LDTs and developing new assays for specific disease states, it gives us an opportunity to work collaboratively as a market and individually with different labs. You will see great things over the next few years, especially with AI and the different sequences that will be looked at. You’ll see a lot more creativity. We’re seeing it now at Bruker ELITech. It’s an exciting time.