The Topaz System (see MS and NGS Play Bigger Roles at AACC 2017) is SCIEX Diagnostics’ first major milestone, according to Aaron Hudson, PhD, senior director of SCIEX’s Clinical Diagnostics Business. SCIEX Diagnostics was formed to focus on the high-growth clinical MS market, and built upon the foundation of that business within SCIEX. Discussing the history of SCIEX Diagnostics, Dr. Hudson told IBO, “We needed a team of people that were just focusing 24-7 on the clinical market. Two-and-half years ago, we introduced SCIEX Diagnostics. SCIEX Diagnostics is an incubator within SCIEX, and we’ve got our own structure within SCIEX Diagnostics. There are about 40 people within it just focused on the clinical market.”

The Topaz is specifically designed for hospital labs. “[I]n the US, you’ve got reference labs, like Quest, ARUP [and] LabCorp, that test a lot of samples sent out from hospitals. The same hospital labs would really like to adopt mass spectrometry, but it’s a little bit difficult to do so because it’s just too complicated,” he explained. “Also, to bring a mass spectrometer in, even if it’s a Class I medical device, they’ve got no assays to put on it, and it would take them probably six months to even validate that system in the lab, never mind develop an LDT.” Most triple quadrupole MS vendors provide MS Class I medical devices.

“They not only start to generate revenue on it to pay off the mass spectrometer, but they also are not paying to send it out to the reference labs as well,” 

In contrast, the Topaz is a Class II medical device when used with SCIEX’s recently introduced FDA-cleared Vitamin D assay kit for the assessment of adult patients for Vitamin D sufficiency. As Dr. Hudson said, “Now, you can actually buy the system and add the Vitamin D assay on top of it, and lock down the system.” Advantages of the Class II system and regulated assay include faster validation. “It takes around a month to validate that in the lab, so much quicker implementation. That’s similar to what it would take to validate an immunoassay analyzer, so [labs] are fairly used to this. Within a month, they can start to get reimbursement dollars because they run Vitamin D.”

The financial return extends beyond the set-up time. Regarding the labs, Dr. Hudson said, “They not only start to generate revenue from [the test] to pay off the mass spectrometer, but they also are not paying to send it out to the reference labs as well.” As he told IBO, the system’s ability to run both the Vitamin D assay and LDTs offer more revenue opportunities. “Most big labs are getting between 150 and 200 Vitamin D assays per day. And even if you just get about 60–70, this [mass spec] pays for itself within 2 to 3 years. Now, in addition to that, what you can do is add your own LDTs on it, because this Topaz system is a locked system if you want to run Vitamin D, but it’s open by design so that you can add additional LDTs on it.” This also allows for the modification of assays, as he explained. “So if new markers come along and it’s a closed system, tough. But now, if you have Topaz, you can do your own LDT and you can add it.”

Future plans for the system include automation. “Because this is a batch system as well, you can prep your sample during the day—it’s manual at the moment but we’re going to launch an automated sample prep [system] at the beginning of next year—you can prep it during the day and just run it overnight,” said Dr. Hudson.

So with the new markers coming out, if you’re actually discovering those on a mass spectrometer, it’s much easier to transfer them to a mass spectrometer test in the future.”

Rather than a 510(k) approval based on equivalence to an existing test, the FDA approval of the new Vitamin D assay was de novo. “As we went through this with the FDA, it became clear that the immunoassay wasn’t really a predicate because when you look at the Vitamin D that the mass spec does, Vitamin D is actually a mixture of multiple analytes,” he explained. “The immunoassay really only measures Vitamin D3. . . . Our mass spectrometer and Vitamin D method individually quantitates D2 and D3, and separates out the epimers, so you get a much more accurate measure of total Vitamin D.” All subsequent MS-based Vitamin D tests for the same indication submitted for FDA approval will have to show equivalence to SCIEX Diagnostics’ test.

The future opportunities for MS-based diagnostic testing are promising, according to Dr. Hudson. “When you look to the future of precision medicine, there’s going to be a whole set of new markers coming out, either with proteomics, metabolomics [or] lipidomics. . . . So with the new markers coming out, if you’re actually discovering those on a mass spectrometer, it’s much easier to transfer them to a mass spectrometer test in the future.” Yet MS will not be the solution in all cases. “I think the future, and precision medicine, is most likely going to be relying on mass spec detection, but I think it is going to be complementary to some of the existing technologies. It’s not going to completely replace immunoassays or routine chemistries—it doesn’t need to.”