NEW YORK (360Dx) – Varleigh Dx and Cancer Research Technology launched a new test for pancreatic cancer this week, with hopes of translating the same protein biomarker for diagnostics in several other cancers.
The companies said the new test, which measures the concentration of antibodies bound to the MCM5 protein, has been CE marked and is available for diagnostic use across the United Kingdom.
The link between MCM5 and pancreaticobiliary cancer was initially discovered and developed by a Cancer Research UK-funded team at the University of Cambridge. Then CRT, the commercial arm of CRUK, licensed the biomarker to Varleigh.
Supporting the new test launch, researchers from University College London also published a study this week in the British Journal of Cancer demonstrating the test can help improve diagnosis of patients with unclear results from standard cytology methods.
According to the authors, diagnosing pancreatic and biliary tract cancer an early stage when curative treatment is feasible remains a significant clinical challenge, even with currently used serum tumor markers, imaging, and other tests and procedures.
The standard method of confirming a malignancy and making patients eligible for surgery is to sample cells from biliary strictures or associated masses, using brush cytology or endobiliary biopsy. These methods have a high specificity (96 percent to 100 percent) for malignancy, but their sensitivity (9 percent to 57 percent) leaves much to be desired, frequently requiring patients to undergo multiple procedures to obtain a final diagnosis, the authors wrote.
Looking for better options, investigators discovered that minichromosome maintenance replication proteins are dysregulated in the biliary epithelium in these cancers, and more specifically, that levels of one of these proteins, MCM5, are elevated in bile samples of patients with cancer.
So they set out to validate an immunocolorimetric ELISA assay for MCM5 in biliary brush samples.
Overall, the researchers tested 97 patients, of which 50 had malignant strictures. Compared with patients' final diagnoses, the MCM5 assay had a sensitivity for malignancy of 65.4 percent compared with 25 percent for cytology alone.
One important caveat, the authors wrote, is that their assay performance was less accurate in certain groups. For example, they saw false-positive results in patients with inflammatory strictures secondary to IgG4-related disease, chronic pancreatitis, and primary sclerosing cholangitis — all conditions that are known to predispose patients to pancreaticobiliary cancer and to be particularly difficult to distinguish from malignancy using conventional diagnostic tests.
Michael Gandy, research and development manager for Varleigh Dx, said in an email that in addition to the new pancreatic cancer test, the company is investigating applications in esophageal and colorectal cancer.
"While some modest further development work is required on the MCM5 assay, clinical trials for esophageal cancer are planned for Q2 2017," he wrote.
"As well as the MCM5 assay itself, these tests also involve the validation of new minimally invasive cell collection devices for esophageal and colorectal sampling which we are developing," he added.
The firm is now in the process of establishing clinical trial sites in the UK to support validation of these next indications for the technology.
Cancer detection and diagnosis, especially less invasive, or noninvasive tests, has become a focus for huge numbers of companies, many of which are investigating much more complex molecular technologies that involve analyzing large swaths of the genome with advanced computation to glean predictive signatures from the mass of information produced.
In particular, several companies advancing liquid biopsy technologies have said they hope to develop their platforms for early pancreatic cancer detection. Trovagene, for example, announced last year that it was investigating the utility of its technology in detecting early pancreatic cancers with the University of Michigan Comprehensive Cancer Center.
Gandy said that Varleigh is tracking the field closely, and is well aware that genomic medicine for both diagnostic and predictive applications is playing an increasingly important role in patient management.
"We are also aware of the health economics associated with the introduction of genomic-based tests, and in our experience there is a place for both traditional protein signature-based assays," he wrote in his email.
"The key [is] in the diagnostic utility of the assay, effective sample collection, test costs, and the clinical positioning within the healthcare pathway," he said.
According to the University College London investigators, very few other tests developed for pancreaticobiliary cancer have so far been successfully incorporated into clinical practice.
Tests like the MCM5 assay, which can be done at the same time as the first diagnostic cytology analysis and can significantly increase the diagnostic sensitivity of this single procedure, have an advantage in that they offer easy incorporation into current practice, as well as into future multimodal methods of stricture assessment, the study authors wrote.