An investigational microarray test that measures miRNA expression patterns to detect the presence of cancer and distinguish between cancers has yielded promising preliminary data, according to CombiMatrix.
The company presented data at the Cambridge Healthtech Institute's Molecular Medicine Tri-Conference in San Francisco last week that showed that its so-called Comprehensive Cancer Array can detect "dramatically different" miRNA expression patterns in the blood of patients with Stage 1 to Stage 4 cancer compared to those who were cancer-free.
Results from the study, which focused on patients with prostate, colon, ovarian, breast, and lung cancers, "indicated that a clear distinction could be made between patients with cancer and those without," CombiMatrix said in a statement "Results also indicated that identification of the specific cancer was possible."
Although the CCA is still in the preliminary R&D phase, CombiMatrix has said it plans to launch it initially as a laboratory-developed test in mid-2010.
When CombiMatrix announced it was developing the CCA last October, CEO Amit Kumar estimated the screening test, intended to be incorporated into people's annual physical exams, could have a $12 billion annual market potential [see PGx Reporter 10-08-2008]
CombiMatrix is planning to market the CCA to the 50 million people in the US who are 40 years or older and charge between $250 and $300 for the ability to simultaneously screen for cancers at multiple organ sites.
According to the abstract presented at the conference, preliminary study data showed that "the microarray platform enables the simultaneous analysis of all human miRNAs by either fluorescent or electrochemical signals and can be easily redesigned to include newly identified miRNAs.
"We show that sufficient miRNAs are present in one milliliter of serum to detect miRNA expression patterns without the need for amplification techniques," the company reported. "In addition, we are able to use these expression patterns to discriminate correctly between normal and cancer patient samples."
In the study, which analyzed 36 serum samples from patients with and without cancer, investigators found that the microarray could detect signals down to 4,000 copies per ml.
"The most obvious observation we can make is that serum levels of miRNAs are up-regulated in cancer patients as compared to normal donors," the study authors said in the abstract. "Furthermore, serum miRNA signatures for various disease states tested are distinct and allow us to distinguish cancer from normal-donor samples using hierarchical clustering, Bayes network, and K* classifiers."
In the study, the investigators were able to distinguish accurately between patients with prostate, colon, ovarian, breast, and lung cancers. "By extending this work with more samples, it will be possible to discover more sets of attributes that will allow accurate classification of other diseases," the investigators state in the abstract.
Speaking to Pharmacogenomics Reporter this week, Kumar said that ultimately the CCA test will be able to answer three questions: Does the patient have a spurious growth? In what organ is the cancerous growth? And at what stage is the cancerous growth?
Initial data from this study showed that the CCA can detect the presence of cancer and determine the affected organ site, according to Kumar. "We're still looking at patient samples to answer the third question," with regard to pinpointing the stage of cancer, he said.
Early detection of cancer gives patients a better chance at getting on the right treatment and survival.
"While early detection and treatment is proven to improve survival for cancer patients, there are no non-invasive, blood-based early screening tests except for those used in prostate cancer," CombiMatrix said in a statement. "As a result, patients tend to delay screening tests such as colonoscopies due to their invasive nature, which reduces the likelihood that such cancers will be detected and treated early."
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The data presented at the recent conference is only the start of a number of studies CombiMatrix is planning for its CCA test. Further data from this and other validating studies will be presented in the coming months, according to company officials.
Since the company is looking to eventually incorporate this test into people's annual physical examination, Kumar acknowledged that there might be direct-to-consumer marketing of this test.
Although "the consumer genomics market is changing, and there are complex regulatory issues at play," the CCA "might eventually have consumer demand," Kumar said, stressing that initially the company will market to physicians.
Furthermore, once the test is launched as an LDT and begins to gain traction in the market, CombiMatrix will begin looking to work with multiple labs to analyze samples. At that point, the company will likely submit the test for clearance by the US Food and Drug Administration, Kumar said.