By Ben Butkus
MONTREAL — Early-stage molecular diagnostics firm QuantumDx said today that it has exclusively licensed from Nanosys the rights to use nanowire field effect transistor biosensors in biomarker detection and sequencing applications.
The pact builds on a previous non-exclusive license agreement between the companies, and will allow QuantumDx to commercialize a handheld, point-of-care molecular diagnostics platform integrating sample prep, PCR amplification, and detection using either nanowire arrays or nanowire-enabled sequencing, company executives told PCR Insider this week.
However, executives said that the company first hopes to commercialize a DNA extraction and fractionation chip based on its own technology as a front-end sample prep product for DNA sequencers and other nucleic acid analysis platforms.
Specific terms of the agreement give QuantumDx exclusive worldwide rights to Nanosys' intellectual property surrounding nanotubes and nanowires for DNA sequencing, detecting nucleic acid biomarkers associated with disease, and other life science applications.
QuantumDx will then use the nanowires as field effect transistor, or FET, biosensors, along with its own proprietary molecular biology, chemistry, and microfluidic technologies in a series of portable devices for molecular diagnostics and DNA sequencing.
In exchange, Nanosys has received an upfront license fee of an undisclosed amount, and will receive downstream royalty payments.
John Burn, medical director for QuantumDx, is slated to discuss the various platforms under development at the company on Saturday in an "Advances in Technology" session at the American Society of Human Genetics conference, held here this week.
"It's difficult to see how it could get better than having a system that actually connects nucleotides directly onto field effect transistors, which in turn are binding DNA instantly and turning it into a computer code with almost no noise," Burn told PCR Insider at the conference.
The nanowire technology was originally developed in the laboratory of Harvard University chemistry professor Charles Lieber, a Nanosys co-founder. Nanosys owns the rights to the IP, and has since 2001 been attempting to develop and commercialize the technology for use in life science and other applications.
Newcastle, UK-based QuantumDx, founded in early 2008, non-exclusively licensed the IP from Nanosys in 2009 to explore its use in DNA sequencing and biomarker detection.
Having demonstrated proof of concept of the nanowires as FET biosensors, QuantumDx expanded the scope of its license with Nanosys and began to map out product-commercialization efforts.
Thus far the company has a prototype point-of-care testing device called Q-POC, which integrates DNA extraction, PCR amplification, and FET biosensing of amplified products onto a handheld device.
For DNA extraction, "we can take whole blood, sputum, saliva, et cetera … [and] we can extract the DNA out in a few minutes, and actually fractionate it," Elaine Warburton, co-founder and CEO of QuantumDx, told PCR Insider in a phone interview.
"We amplify those up, and then we run those across a … nanowire FET biosensor, where we record electrical signals, and convert DNA to binary code that can then easily be read by a computer," she added.
The sample prep portion of QuantumDx's device, partly developed in house and partly based on technology licensed from various organizations, is based on a sorbent filter and microfluidic channels in a chip about the size of a microscope slide.
The filter works much like chromatography by "basically stripping the sample of all the gunk except DNA and water," Warburton said, and will likely form the basis of QuantumDx's first product, a DNA extraction and fractionation chip for use on the front end of nucleic acid analysis platforms from other companies.
As such, QuantumDx hopes to forge partnerships in this area over the next several months with the hopes of releasing a product within a year, Warburton said.
The PCR amplification portion of the Q-POC platform will use another microscope slide containing multiple microfluidic channels through which purified DNA will travel. The chip is then placed on multiple adjustable heating pads to provide various temperature zones for thermal cycling. QuantumDx plans to use off-patent PCR chemistries to minimize cost.
This portion of the Q-POC platform may be "less exciting" than the nanowire FET biosensors, Burn said, but could end up being QuantumDx's bread and butter ahead of the commercial release of Q-POC.
"It's a bit like the guys who sold wheelbarrows in the Klondike, who made a lot more money than the guys who found gold," Burn said. "Basically those two pieces together can turn anything into a PCR product in 10 minutes … for a few dollars, and that's got huge applications [for] existing technologies. So they're not exciting at one level, but for the people in the business of diagnostic testing, it's very exciting."
Following the sample prep product, QuantumDx plans to commercialize a Q-POC system that uses the FET biosensors in an array format to detect the amplified DNA. Warburton said that the company hopes to have this device in clinical trials in 18 months, but that it will likely test it in developing regions of the world first because of its great potential in that setting.
Warburton said that Lieber and other researchers have published copious amounts of data demonstrating that nanowires can be effective and ultra-sensitive biosensors. However, QuantumDx has actually "dumbed down the sensitivity" by functionalizing the biosensors with its own reversible charge terminating nucleotides that effectively enhance the electrical signal when there is a DNA binding event.
"Many other point-of-care devices give yes-or-no answers, but we'll be able to provide a definitive answer, let's say, for a particular infectious disease panel; or a [sexually transmitted disease] panel," Warburton said.
"Not only will we be able to identify the infectious agent family … but also its drug-resistance status," she added. "We're looking at between 15 or 20 minutes, once we've optimized everything, from sample to answer. And the result will be shown on the handheld device and can be transmitted back to a central location."
Besides STDs, QuantumDx is also considering tests for warfarin sensitivity and drug-resistant tuberculosis.
Finally, QuantumDx has done initial proof-of-concept work demonstrating how the FET biosensors can be used for DNA sequencing, and the company hopes to eventually commercialize a version of Q-POC that can perform sequencing on clinical samples at the point of care.
"We will end up with the ability to sequence long read lengths and short read lengths, and do shotgun sequencing, on a handheld device," Warburton said. "This is really useful for very accurate disease detection and pathogen detection."
Jonathan O'Halloran, co-founder and CSO of QuantumDx, told PCR Insider that such a device would be particularly useful for analyzing and diagnosing infectious agents with highly variable genomes, such as HIV.
"We have the opportunity to be able to sequence the genome at the point of care, and there are a lot of issues we need to iron out first, but ultimately that would strike me as a much better approach than PCR because the genome is so variable," O'Halloran said.
To finance its product development, QuantumDx in August closed a financing round for an undisclosed amount; and thus far has reeled in the equivalent of about $1.2 million in research grants from the UK government, Warburton said. She also said that the company expects to receive an additional large bolus of government funding sometime in the next few weeks.
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