By Ben Butkus
Seegene in the coming week will unveil a new technology that enables highly multiplexed melt curve analysis on existing commercial real-time PCR instruments, a technology that it said represents the next generation of its existing multiplex PCR and real-time PCR assays.
A company executive said this week that by the end of this year it hopes to obtain CE Marking and commercialize its first molecular diagnostic tests incorporating the technology — namely, assay panels for respiratory viruses and sexually transmitted diseases.
In the meantime, Seegene is "still developing" its strategy for shepherding various molecular diagnostic tests based on its existing multiplex PCR through the US Food and Drug Administration approval process, the executive said.
Seegene's most recently developed technology is called TOCE. The name is an acronym, but the company declined to disclose its meaning due to the early and proprietary nature of the technology, Dave Dolinger, vice president of business development for Seegene, told PCR Insider this week.
TOCE, which the company will demonstrate for the first time at next week's American Association for Clinical Chemistry meeting in Atlanta, was developed by Seegene scientists as a way to increase the multiplexing capability of melt curve analysis.
According to Seegene, melt curve analysis has to this point been hampered by several inherent limitations, including constrained probe design, the inability to extensively and efficiently multiplex, and high sensitivity of melting curves due to sequence variation of the probe site.
TOCE technology overcomes these limitations by allowing multiplexing in a single fluorescence channel; by providing consistency in Tm value regardless of sequence variation; and by providing a level of sensitivity equivalent to that of probe-based singleplex real-time PCR, the company said.
"We've always been stuck in the dogma where, if we have a real-time instrument that has four channels, we can detect four dyes, and that's it," Dolinger said. "[TOCE] allows us to expand beyond that and detect up to at least four different targets per channel."
Prior to developing TOCE, the company already had three major PCR assay platforms incorporating two of the company's proprietary chemistries: Seeplex endpoint PCR, which uses dual-priming oligonucleotide, or DPO, technology; Anyplex multiplex real-time PCR, which uses real amplicon detection, or READ, technology; and Magicplex multiplex real-time PCR, which uses both the DPO and READ Technology.
All of these assay chemistries are capable of a high degree of multiplexing, but, according to Dolinger, Seegene's assay development efforts have been hampered by a lack of commercial instrumentation having the ability to fully exploit the chemistries' potential.
"It has limited us in how we go about our design of assays," Dolinger said. "We still haven't gotten over that instrument hurdle. Instead of trying to wait for someone to come up with a 16-channel real-time instrument, we are able to adapt standard instruments currently in common use in clinical labs to be able to do complex multiplexing."
So far, Seegene has tested the TOCE technology on several real-time PCR instruments, including Life Technologies' ABI 7500 and Cepheid's SmartCycler, both four-channel instruments; and Bio-Rad's CFX96, a five-channel instrument.
As the "next generation" of Seegene's DPO and READ technologies, TOCE "in essence has opened up a new avenue that allows us to really multiplex to the level that we need to provide assays more along the lines of panels than specific assays," Dolinger said.
The company's first application of TOCE will be a respiratory test that simultaneously detects 16 respiratory viruses and five pneumonic bacteria; followed by a test for STDs that simultaneously detects seven pathogens.
Dolinger said that the company hopes to be able to commercialize these news tests by the end of the year with CE Marking.
Commercializing the assays in the US, however, is a longer-term proposition. "We feel that we have to introduce this to the FDA and really have them understand it fully, so that they'll appreciate the capabilities of the technology," Dolinger said. "Then we'll be able to work with FDA on how we can take these assays through the approval process."
In the meantime, Seegene already sells several Magicplex and Anyplex tests with CE Marking, such as tests for seasonal influenza A subtype H1, H3, and 2009 novel H1N1 in Europe and Asia; a test for multiple diarrhea-causing viral agents in Canada; a multi-pathogen screening test that can identify more than 90 top sepsis-causing pathogens; and a test for simultaneously detecting tuberculosis and genetic mutations for multi-drug-resistant TB.
None of Seegene's tests have received approval in the US, but the company will continue to pursue this goal for molecular diagnostic tests that use its existing technologies, particularly the Anyplex assay chemistry, Dolinger said. "They are very powerful in what they are able to do, and there are unmet needs that they are able to address," he said.
Seegene is headquartered in Seoul, South Korea, with US offices in Rockville, Md., and European offices in Eschborn, Germany.
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