Asuragen this week announced that it will begin marketing early next month a microRNA diagnostic assay designed to differentiate pancreatitis from pancreatic ductal adenocarcinoma, making the company the first to commercialize a test based on the small, non-coding RNAs.
However, whatever edge the product launch may give Asuragen in the miRNA diagnostic market is likely to be short-lived since its two chief rivals, Rosetta Genomics and Exiqon, are poised to introduce later this year their own miRNA tests, albeit for different indications.
“The definitive diagnosis of pancreatic cancer can be quite challenging, particularly in patients displaying chronic pancreatitis,” Gregory Tsongalis, director of molecular pathology at Dartmouth Hitchcock Medical Center and an Asuragen collaborator, said in a statement. “This microRNA test could become a valuable asset in patient management and diagnosis of pancreatic cancer.”
In 2007, researchers from Asuragen and Ruhr University published data in Oncogeneshowing that they could use changes in miRNA expression to classify normal pancreas, chronic pancreatitis, and pancreatic cancer.
Specifically, the investigators identified 26 miRNAs that are most prominently misregulated in PDAC. They found that expression signatures of two miRNAs, miR-217 and miR-196a, could be used to distinguish healthy pancreatic tissue from pancreatitis and cancerous samples.
“Comparing differentially expressed genes from PDAC with predicted miRNA target genes for the top 26 miRNAs, we identified potential novel links between aberrant miRNA expression and known target genes relevant to PDAC biology,” the research team wrote in Oncogene.
That year, two different research teams from Ohio State University published data in the International Journal of Cancerand the Journal of the American Medical Associationsuggesting that pancreatic cancer may have a specific miRNA expression pattern that could potentially be used diagnostically.
According to Asuragen, its new diagnostic assay can be performed on either frozen or formalin-fixed, paraffin-embedded tissue samples. In a blinded validation study of 60 frozen clinical samples, the assay achieved a sensitivity of 95.2 percent and a specificity of 94.9 percent. Validation of the test for use with fine-needle aspiration specimens is ongoing, the company added.
“The definitive diagnosis of pancreatic cancer can be quite challenging, particularly in patients displaying chronic pancreatitis. This microRNA test could become a valuable asset in patient management and diagnosis of pancreatic cancer.”
Earlier this year at the University of Miami’s Winter Symposium, which focused on regulatory RNA in biology and human health, Asuragen researchers and collaborators presented data showing that altered expression of miR-217 and miR-196a could be used to distinguish benign pancreatic tissue samples from malignant ones obtained through fine needle aspiration.
According to that data, 13 patients with suspected pancreatic masses underwent endoscopic fine needle aspiration biopsies, which were collected and stored in Asuragen’s RNARetain sample collection and RNA stabilization solution. Normal pancreatic tissue specimens were collected ex vivo from resected pancreas.
“We observed that the quantitative expression analysis of selected miRNAs and mRNAs in PDAC and normal pancreas [fine needle aspiration] samples correlated well with the changes observed in respective frozen tissue samples,” the investigators wrote in a poster presented at the symposium. “In addition, we verified that altered expression of miR-196a and miR-217 enabled clear segregation of PDAC [fine needle aspiration] specimens from non-malignant … samples.”
Head of the Queue
Asuragen was created in 2006 out of the diagnostics and services division of Ambion that wasn’t acquired by Applied Biosystems to pursue the development of cancer diagnostics and therapeutics using miRNAs (see RNAi News, 1/5/2006).
Since that time, the company has remained fairly tight-lipped about its progress. Although Asuragen did announce last month the creation of a spinout called Mirna Therapeutics that will focus on miRNA-targeting therapeutics (see RNAi News, 4/3/2008), specific details about its diagnostic pipeline have not been forthcoming.
Asuragen’s chief rivals in the field, Rosetta and Exiqon, have made no secret of their intentions to play in the miRNA diagnostic field and both have said they plan to introduce products this year.
But Asuragen’s announcement this week means the company has jumped to the head of the commercialization queue.
Despite the impending milestone, the company’s lead is likely to be small. Rosetta has already submitted for approval by the New York State Department of Health its first miRNA diagnostic, designed to differentiate squamous from non-squamous non-small cell lung cancer (see RNAi News, 4/10/2008).
The Israeli company is also planning on introducing two other tests, one for differentiating lung adenocarcinoma from mesothelioma and one for identifying the source of cancers of unknown primary origin, before the end of the year.
At the same time, Exiqon recently completed its acquisition of California-based oncology-testing services provider Oncotech, through which the company plans to market its first miRNA diagnostic this year.
The test’s indication has not been disclosed, but Exiqon President and CEO Lars Kongsbak told RNAi News last month that it would likely be a replacement for Oncotech’s cellular-based extreme drug-resistance test for colon cancer.
While it seems that all three companies are, for the moment, looking to address different segments of the cancer testing market, they do have one thing in common: their marketing strategies.
Asuragen said that its pancreatic cancer assay would initially be available through its CLIA laboratory, an approach Exiqon is also taking with Oncotech’s CLIA laboratory. Rosetta, meanwhile, has signed deals to market its miRNA diagnostics through the CLIA laboratories of Columbia University Medical Center and the University of California, Irvine.
As reported by RNAi News sister publication Pharmacogenomics Reporter, the US Food and Drug Administration said that it would begin regulating so-called home-brew diagnostics commercially available through clinical laboratories. However, it is not yet clear how this oversight will impact miRNA tests.