NEW YORK (GenomeWeb) – As many companies gear up to compete in the blood-based cancer detection space using technologies that analyze mutations in circulating cell-free DNA or circulating tumor cells, Belgian diagnostics firm VolitionRx has taken what it believes is a unique approach toward the same end.
The company is advancing a technology its calls NuQ for isolating and analyzing circulating nucleosomes, with its first commercial product for colon cancer scheduled for launch in Europe this year.
Unlike most ctDNA-based diagnostics, which rely on PCR assays or next-gen sequencing to detect specific DNA alterations shed by a tumor into the blood, Volition's technology takes a simpler tack, using basic ELISA to detect and quantify various features of circulating nucleosomes, including histone modifications, DNA methylation patterns, and analysis of other protein features of the nucleosome.
VolitionRx plans to launch its first commercial assay using the technology by the end of this year in Europe — a colorectal cancer test made up of a panel of several individual ELISAs targeting different aspects of the nucleosome complex.
In preparation for this, the company has been pursuing CE marks for each individual biomarker assay — three so-far for its NuQ V001, NuQ T003, and NuQ X001S.
NuQ V001 and NuQ X001S target specific epigenetic cancer signals within the nucleosome, while the NuQ T003 test targets the whole nucleosome.
"We're not intending to sell the individual assays, but we have been CE marking each one to build our familiarity with the process and support ISO certification of our lab. Then when we decide on the final panel, we will CE mark and launch the whole thing," VolitionRx CEO Cameron Reynolds told GenomeWeb this week.
VolitionRx is also planning the first steps in seeking US Food and Drug Administration approval of its assays, he added.
"We have been discussing with several CROs the possibility of … 510K trials, though a few of our tests in development will likely also go through PMA process, where they may be likely to be used for screening, like in colorectal cancer. That will require bigger studies, but there are also uses for the product in symptomatic or high-risk populations, where we think we can go through the 510k process," Reynolds said.
Unlike broad sequencing of ctDNA, which costs in the thousands of dollars, Reynolds said that because of the simplicity and low-cost of ELISA technology, VolitionRx believes its tests can achieve widespread use.
A relatively lower cost also poises the technology for potential use in lower-resource countries and in the developing world, according to Reynolds
And despite relying on relatively simple technology, VolitionRx believes its approach can deliver tests with high enough sensitivity and specificity to be impactful and attractive to clinicians.
By targeting epigenetic changes, which are hypothesized to occur early in the development of a malignancy, VolitionRx believes it has an advantage in sensitively detecting incipient cancer or pre-cancer.
Earlier this year at the annual meeting of the American Association for Cancer Research, VolitionRx researchers with collaborators from the University of Surrey in the UK shared data from several of the company's ongoing studies in colorectal, pancreatic, prostate, and lung cancer.
From the colorectal cancer study, the investigators reported that in a small group of 121 patients referred for colonoscopy at Belgium's University of Namur, a panel of five of the company's nucleosome biomarker assays detected 87 percent of colorectal cancer cases and 67 percent of dysplastic polyps at 90 percent specificity.
According to Jake Micallef, VolitionRx's chief scientific officer, larger colorectal cancer studies involving up to 14,000 patients are now in progress.
In the same AACR Poster, VolitionRx scientists also reported that in a study of 73 non-small cell lung cancer patients — conducted with Liege University Hospital in Belgium — a panel of four epigenetic nucleosome assays combined with assessment of patients' smoking history detected 93 percent of NSCLC cases with 91 percent specificity.
And, in a 59-subject collaborative study with Lund University in Sweden, the company found that a panel of four nucleosome ELISAs, along with the protein biomarker CA19-9, could detect 92 percent of stage II pancreatic cancer cases with 100 percent specificity in healthy subjects, and only two false positives among patients with benign pancreatic disease.
Micallef told GenomWeb that the company is still working out the format of its colorectal cancer test — whether it will be a collection of individual ELISAs, or perhaps involve multiplexing, or what he called a "pseudomultiplexing" strategy.
"Anything that's possible with ELISA is possible with what we're doing," he said. "We've been talking to a few companies that can multiplex and doing a few pilot studies in that regard, but in the moment, we are mainly doing single assays on standard plates.
"Although we have a lot of different assays, it's really just a lot of different labelled antibodies, so we can also run a kind of pseudomultiplex, where we … just add different antibodies to different rows," he added, but the final product will probably be customer-driven. "We are agnostic," he said.
Though the company hasn't solidified its plans for further test launches, Reynolds said that VolitionRx is advancing promising assays in pancreatic, lung, and prostate cancer.