By Ben Butkus
Having recently been awarded a key patent covering its core microfluidic sample-processing cartridge technology, PositiveID subsidiary MicroFluidic Systems is ratcheting up its R&D and partnering activities in an attempt to commercialize a rapid, multiplex, real-time PCR-based molecular diagnostic device incorporating the technology.
The device, called Dragonfly, is at least a year and a half from marketability, but has the potential to obtain a CLIA waiver based on its push-button, sample-to-answer design, a company executive said this week. The firm believes it will enable molecular diagnostic assays for a variety of infectious diseases at a cost of between $5 and $10 per test.
In the meantime, MicroFluidic Systems, or MFS, is positioning its instrument in the near term for the biodefense, homeland security, and disease surveillance markets — all areas the company is intimately familiar with.
"Our target is first that defense market, mainly because that's where our experience is, and we are continuing to develop assays for that," Lyle Probst, vice president of program management for MFS, told PCR Insider this week. "But we've branched out from that … into [clinical diagnostics], and that will take a little more time … and we definitely need to partner [with] a larger corporation that can do the mass production and take it through [US Food and Drug Administration] approval."
MFS was founded in 2001 by current president and CEO Allen Northrup, who previously co-founded Cepheid and was its chief technical officer and vice president of research.
The company got its start by using funding from the US Department of Homeland Security to develop a product called the Microfluidics-based Bioagent Autonomous Networked Detector, or M-BAND, an airborne biothreat-detection system.
M-BAND, however, "is a large instrument that's like a whole lab in a box," Probst said, and thus isn't ideal for use in clinical diagnostics or even biodefense applications where portability might be beneficial.
The company has since developed DragonFly, essentially a miniature version of M-BAND that sits on a lab bench and processes test cartridges pre-loaded with specific molecular diagnostic assays.
Last May, in the midst of DragonFly's development, medical technology firm PositiveID acquired MFS in a deal worth up to $8.2 million depending on various revenue and earnings targets (PCR Insider, 5/19/2011).
With MFS' original financial support from the US government having dried up, the PositiveID acquisition provided the outfit with additional R&D support to continue developing and testing DragonFly, which MFS has been doing over the past year.
"The Dragonfly platform is two parts — the cartridge, which is meant to be a disposable; and then the instrument that … processes the sample," Probst said. "We've built a handful of them to do all our proof-of-concept work … for multiple types of organisms in multiple samples. We've done blood samples, urine, nasal and buccal swabs, and environmental samples. We've done viruses, such as influenza; as well as [human papillomavirus], [methicllin-resistant Staphyloccus aureus]; and then all the major biothreat organisms."
Probst added that the DragonFly's test cartridges contain the assay specifics, while the "instrument itself that sits on the bench is agnostic. It doesn't really care what you put on it – so we can have a cartridge for influenza, or anthrax, or pick an organism."
Earlier this month, MFS won a US patent covering the technology — No. 8,133,451, entitled "Sample preparation apparatus." (PCR Insider, 3/20/2012).
MFS' DragonFly model is similar to that of Cepheid and its GeneXpert system, and not a coincidence given Northrup's background. Northrup discussed some of the nitty-gritty technical differences between the two platforms with PCR Insider last year following the PositiveID acquisition.
This week, Probst discussed a few other broad differences between the DragonFly and GeneXpert.
"With the cartridge, we can input the liquid sample, and it processes it from sample input to data output in 30 minutes or less, depending on what it's processing," Probst said. "Some things are in the 22-minute range. But we purposefully kept it under 30 minutes … to take a raw sample, purify the raw nucleic acid, and then do a TaqMan PCR assay."
In comparison, Cepheid's GeneXpert can perform sample-to-answer tests in anywhere from about 40 minutes to two hours, depending on the organism and sample type, according to various product literature on the company's website.
"The reason we are going that route is for ease of use; and also so we can go for a CLIA waiver on it, because the instrument itself will just have a single button," Probst said. "Once you load the cartridge, you'd just push the start button and it does everything from there and reports the results out."
In addition, MFS plans to embed PositiveID's radio-frequency identification chips in the DragonFly system. "This is a very small RFID, about the size of a pencil lead, and each of those will be coded with the contents of the cartridge," Probst said. "If it's an influenza cartridge, that will have a unique identifier in it, so when you put it into the instrument it reads the RFID and knows what program it needs to run for that particular sample."
Further, Probst said that MFS is targeting a cost per test cartridge of $5 to $10, "so it's truly a disposable." He also said that the DragonFly instrument will cost somewhere between $15,000 and $20,000.
The prices for Cepheid's tests vary; however, in 2010 when the company launched its Xpert MTB/RIF assay for tuberculosis and rifampin resistance, a company spokesperson told PCR Insider that an Xpert MTB/RIF test cost around $64 and a GeneXpert system normally costs in the neighborhood of $30,000 (PCR Insider, 9/2/2010). Through a compassionate pricing program for developing nations through the Foundation for Innovative New Diagnostics, Cepheid reduces the cost of the GeneXpert to under $20,000 and the cost of a test to around $16, according to FIND's website.
Lastly, MFS is developing two different versions of DragonFly – one that has an integrated readout on a built-in screen; and another that can report results out to a network for applications such as global monitoring of disease outbreaks.
MFS has also developed a proprietary real-time PCR assay scheme that uses a combinatorial detection algorithm to enable a high degree of multiplexing — potentially up to 30 targets, Northrup said last year — which is currently not feasible with commercial real-time PCR platforms.
Probst said that MFS has already published a white paper on its website demonstrating the robustness of this assay to detect multiple biothreat organisms, "and we're looking at using that same method for other organisms and applying it to the DragonFly cartridge. So it will be a highly multiplexed cartridge. We have a design and have built prototypes to be able to perform real-time multiplexed PCR."
Having built these capabilities out and secured one of its key patents, MFS is now doubling up its efforts to identify a potential clinical diagnostics partner to move DragonFly forward and begin conducting preclinical trials.
"One thing we were waiting on was our patent," Probst said. "And because we're currently working on partnerships, we haven't put a whole lot out there just yet in terms of publications."
He added that a "rough timeframe" for when the company might be able to begin manufacturing the system "is anywhere from about a year and a half to two years from today. But that's going to depend on who the partner is and who the end customer is for the first units that are out there."
Probst said that MFS is currently working on an assay for avian influenza." We already have an H1N1 assay, and we are working on an H5N1 [assay]," he said. "We are looking at that as a start for breaking into that market. Every year there is a flu outbreak, and every year there is a need to get out into the field and take samples … quickly and inexpensively … which is one of the barriers to identifying and quickly responding to an influenza outbreak."
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