VolitionRx Uses Nucleosome Technology for Early Cancer Diagnosis
Cameron Reynolds CEO, VolitionRx Jake Micallef, Ph.D., CSO, VolitionRx VolitionRx (Belgium) is tackling cancer diagnostics 160 base pairs (BP) at a time. The company’s nucleosome- based detection technology is able to detect, measure, and analyze cancer-causing mutations using a drop of blood on widely available enzyme-linked immunosorbent assay (ELISA) platforms. The company will commercially roll […]
Jake Micallef, Ph.D.,
VolitionRx (Belgium) is tackling cancer diagnostics 160 base pairs (BP) at a time. The company’s nucleosome- based detection technology is able to detect, measure, and analyze cancer-causing mutations using a drop of blood on widely available enzyme-linked immunosorbent assay (ELISA) platforms. The company will commercially roll out the first of its NuQ tests—for colorectal cancer (CRC) detection— in Europe later this year, while it completes further validation on NuQ tests for prostate, lung, and pancreatic cancer.
The company believes its low-cost, noninvasive test is a solution for the compliance problem associated with other CRC screening methods and could establish itself as an accurate screening test in other cancer areas. DTET recently spoke to VolitionRx’s CEO Cameron Reynolds and Chief Scientific Officer Jake Micallef, Ph.D., about the company’s technology and upcoming commercialization plans.
Why is your technology based on nucleosomes? Micallef: Actually, nucleosomes are the biomarker that everybody is using right now, although they just are not calling it that. Most of the companies involved in new cancer detection technologies in blood look at DNA sequences. As the name suggests, circulating tumor DNA (ctDNA) technologies analyze tumor DNA that is circulating in the blood. If you can find cancer mutations in that ctDNA that means the patient has a tumor somewhere.
If you look at published papers, you will find that ctDNA is very short fragments— less than 200 BP—and with more accurate detection, papers specify 160 BP, exactly the amount of DNA bound to a nucleosome. DNA does not circulate in the blood in the hypothetical double helix. It doesn’t exist that way outside of a molecular biologist’s test tube. In cells, DNA is always protein bound as a nucleosome.
So, what we’re looking at is the same thing everybody is looking at, but the main technical difference is that other companies have a DNA extraction step. They take the DNA off the nucleosome and then it is just the double helix and short pieces of DNA. We are looking at the same target, but instead of looking for just the DNA bit of the target, we are looking at the whole nucleosome. It has been known for 20 years that the whole nucleosome structure is changed in the presence of cancer cells—the epigenetic changes. We look at whole structural changes, as opposed to just the sequence changes.
What are the advantages of using nucleosomes instead of ctDNA? Micallef: The advantages of doing this are a few-fold. In the GRAIL (Illumina) announcement, it said their aim was to try to reduce the cost of a ctDNA test down to about $1,000. Our test costs dramatically less than this. We are not talking about a marginal cost difference. We are talking about a completely different ball game. That is because we use ELISA, which has been established for 30 years. It is a robust and mature technology.
The other advantage is that, in general, in order to find one mutation in a sequence 160 BP long, if you could target the whole 160 BP sequence from the 3 billion BP in the human genome, you are talking about one part in tens of millions. You need quite a lot of blood for that—most need five mL to 10 mL of blood. We use 10 μL, which is equivalent to about a drop of blood. In addition, our test can be run during an annual blood draw, for example, with a cholesterol test.
How do you select the clinical applications for the nucleosome technology? Reynolds: Basically there are hundreds and hundreds of changes in physical structure on the nucleosome, which are under our proprietary intellectual property portfolio. Each cancer has some of these changes that are similar to other cancers and some that are different from each other. We could have gone with any cancer early on because they all seemed to work very well. We went with CRC first purely opportunistically because it is currently screened for regularly. We could work with very large organizations to collect blood before colonoscopy. Given that colonoscopy is an accurate diagnostic, we had a very good gold standard to measure against. And because there are populations that are screened through the colonoscopy or fecal tests, we could run very large, low-cost trials, where the case has already been made for screening.
In CRC, we have trials that have gone head-to-head with both colonoscopy and fecal tests. As a small company, doing a large trial in lung or pancreatic is a lot more difficult because there are not screening programs in the general population for those cancers.
We are looking at other conditions now. We start with the biggest cancers. Our earliest targets are colorectal, lung, prostate, and pancreatic. We will look at breast and then move into less common cancers.
Can you tell us about the company’s commercialization strategy? Reynolds: We aim to have a product to sell this year, which is a big milestone, but it will take time. We will have a large amount of data coming out this year and next year too. Our CE mark allows us to sell clinically in Europe, but the size of study to get a CE mark isn’t very large. We are doing large studies in Denmark, in symptomatic and screening populations of about 19,000 patients, to convince key opinion leaders and the government that the test is worthy of buying and adopting. We have data from the first 4,800 patients and we are processing the last 14,000 in a symptomatic population study. It is going to take some time to start marketing directly to medical professionals and key opinion leaders and governments in Europe. It will take a few years to get full access, but I think we have a very compelling case. In Europe there are not many colonoscopies given for screening purposes, but fecal tests have a lot of issues with compliance.
In the United States, we are going to apply for a 510k in a symptomatic population, while we are getting a large screening study done in CRC. We will also apply for 510K as quickly as we can in lung and pancreatic cancers. Although these are smaller markets, we believe we can help the high-risk and symptomatic populations in the short term. Our aim is to start the process with the U.S. Food and Drug Administration (FDA) this year, get a CRC screening trial done next year, and get 510k for lung and pancreatic in 2018. We believe we have something unique. While we are keen to do the large screening PMA trial for FDA approval, it can take several years. We can help other patients in the meantime by going through the 510k process to make the tests available.
We never intended to establish our own CLIA lab, but we have been in discussions to license our technology for laboratory developed test development in parallel course with the FDA. Our main aim is to go the FDA route. We have very solid intellectual property. We have a very simple test. Being on a simple platform we can do lots of different things at the same time. Our aim is to get it out and as broadly as quickly as possible, in as many ways as possible, to help as many people as we can. We think in terms of Android rather than Apple. We want to get our license used by lots of different people on different platforms.
How will cancer screening and diagnostics evolve in the next few years? Micallef: Currently, most cancer diagnostics are based on scanning—mammography and low-dose CT imaging. The actual diagnosis of cancer will always be based on identifying the lump or lesion and sampling it with histochemical methods. The diagnosis will be the same, but the detection of cancer, within five years, will use far more blood tests. The detection of cancer through blood tests will become the norm. The scanning methods will never become obsolete. If you have a blood test that says lung tumor, the clinician still needs a scan to see how big, where it is, and how to cut it out. If they can’t find it on the scanner they will monitor with further blood tests. Scanning methods will be used as part of diagnosis, not detection.
Reynolds: People realize, short of curing cancer, the next best thing is to diagnose early and have it removed. Currently there are real problems with pretty much every diagnostic out there because of compliance or invasiveness. The blood test will become a very important part of the mix. Very few years down the road we plan to have our tests as a primary or adjunct test for three or four major cancers. They will help make the cancer diagnosis early and with highly compliant tests. People forget the accuracy of tests for people who never take the test equals exactly zero. So a low-cost, highly compliant blood test will really help revolutionize how early and how often cancer is found.
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