By Ben Butkus
Clinical diagnostics firm Randox Laboratories this quarter expects to receive the CE IVD Mark for a trio of multiplex molecular diagnostic panels to detect respiratory pathogens, sexually transmitted infections, and KRAS/BRAF/PIK3CA mutations, a company official said this week.
The ensuing commercial launch of the tests will mark Randox's first major foray into the molecular diagnostics market, a venture it plans to continue by launching additional tests for breast cancer sub-typing, cardiac risk prediction, and hypercholesterolemia mutations, among others, likely by the end of the year, the official said.
Randox, headquartered in Crumlin, UK, unveiled its new molecular diagnostic arrays last week at the Molecular Medicine Tri-Conference in San Francisco. The company has for the past 30 years played primarily in the clinical chemistry market, and currently supplies more than 60,000 laboratories in more than 130 countries, making it the sixth largest manufacturer of clinical chemistry reagents in the world, according to the company.
On the clinical diagnostic front, Randox has traditionally developed and marketed immunoassays, many of which it offers in an array-based format for high-throughput, multiplexed analysis on a detection platform called Evidence Investigator.
As such, the company already had the microarray and chemiluminescence expertise and technologies in place. In 2009, Randox signaled its eventual move into molecular diagnostics when it non-exclusively licensed from Seegene its Dual Priming Oligonucleotide, or DPO, technology and indicated that it would use the tool to develop high-throughput diagnostic screening panels to detect a variety of pathogens.
Scott McKeown, an R&D consultant for Randox, told PCR Insider this week that the company indeed still uses the DPO technology, as well as several follow-on Seegene assay technologies, in its molecular diagnostic arrays.
"We've been working very closely with Seegene," McKeown said. "Everything in our portfolio of molecular diagnostic tests right now [uses] Seegene. There are a couple of different types of primers made by Seegene … and they work very well for us for different applications."
In addition to DPO, Seegene also has developed a PCR assay chemistry called real amplicon detection, or READ; as well as a multiplex high-resolution melt chemistry it calls TOCE (PCR Insider, 7/21/2011). All of Seegene's primers and assays are designed to enable a high degree of PCR multiplexing without sacrificing sensitivity or specificity. McKeown didn't specify which of these other next-generation assay technologies Randox uses.
By adding these PCR chemistries to the mix, Randox can now offer a molecular diagnostic workflow that combines highly multiplexed, single-tube PCR; array-based amplicon hybridization; and chemiluminescence detection on the Evidence Investigator.
"We designed the arrays to sit very much in line with what labs are currently doing for this type of testing," McKeown said. This typically involves extracting DNA, performing PCR – "usually on a single-pathogen or -mutation basis," McKeown said – then using some sort of endpoint method to detect amplicons. Alternatively, many labs currently use real-time quantitative PCR, but that technique is still limited to around half a dozen separate targets.
"We've developed our assay so you still do your standard [DNA] extraction as per normal, but then you take your extracted DNA and use the Randox kit and the multiplex one-tube PCR approach to cover all the targets on that array at one time," McKeown said.
That part of the protocol is "off-chip," he explained, and the PCR can be performed in any standard thermal cycler.
"Then, part of the assay is on-chip, where you put your amplicons onto the biochips for hybridization," McKeown said. "So it's part off-chip and part on-chip."
Depending on the diagnostic array, users will be able to obtain a result three to five hours after the nucleic acid extraction step. Randox's STI panel tests for 10 of the most common sexually transmitted pathogens, including bacteria and viruses. Meantime, its respiratory array covers 22 targets; and its KRAS/BRAF/PIK3CA array – which detects mutations used to stratify colorectal cancer patients for EGFR-targeted therapy – covers 20 mutations.
The company already faces stiff competition on the multiplex molecular diagnostic front, particularly from companies developing or marketing panels for infectious diseases.
Chief among these is Idaho Technology, whose 15-target, HRM-based FilmArray Respiratory Panel received 510(k) clearance from the US Food and Drug Administration last April (PCR Insider, 4/28/2011). In February, Idaho Tech also filed for clearance of five additional pathogens; and the company has said it plans to add blood culture testing and gastrointestinal infection panels.
Seegene could also be considered a competitor, as it is non-exclusively licensing its multiplex PCR technology to other partners, and has marketed or is developing its own molecular testing platform. Meantime, startup PrimeraDx is developing a platform that marries highly multiplexed endpoint PCR and capillary electrophoresis on an integrated system.
Another established competing multiplex platform is Luminex's xTag Respiratory Viral Panel; while on the EGFR-targeted therapy front, Qiagen's Therascreen KRAS assay tops a rapidly growing list of competitors.
McKeown acknowledged that competition in the space is getting fiercer; but, he added, judging from feedback he received at last week's Tri-Con conference, the company is confident that it has the upper hand in some areas.
"It's not just having one test, but having several really good tests on the same platform," he said. "And also having the market reach [that Randox has] – so a company that's able to put the test out globally was also seen as a huge advantage. Third, flexibility, in terms of developing and tweaking the assays on individual project needs. On all those fronts, Randox stood head and shoulders above a lot of the other platforms and technologies that are out there."
Randox also plans to release a number of additional molecular diagnostic arrays using essentially the same technology and workflow. Following CE Marking of the STI, respiratory, and KRAS/BRAF/PIK3CA tests, the company will continue developing tests including a breast cancer expression array for tumor subtyping; a cardiac risk prediction SNP array; a familial hypercholesterolemia mutation array; and various pharmacogenomic arrays.
McKeown said that those follow-on products are "pretty close to the wire, and will not be far behind [the first three tests]. We're hoping to get those out by the end of the year."
The company will also eventually pursue FDA approval for its molecular diagnostic arrays, but it hasn't yet begun this process or established a timeline for such an endeavor.
"We'll be taking the biochip [format] forward," McKeown said. "A lot of companies will take a technology onto a chip and then move onto something else, whereas this is a technology that we see as being very much adaptable and flexible to take forward for years to come."
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