NEW YORK – Mesa Biotech has entered the clinical validation stage of a molecular diagnostic test for SARS-CoV-2, the virus that causes coronavirus disease COVID-19. The test runs on the firm's handheld system, which is already CLIA waived in the US for influenza testing.
The test is currently being clinically validated in collaboration with researchers at the coronavirus reference laboratory at the Centers for Disease Control in China, the firm's CEO, Hong Cai, said in an interview.
In Mesa's lab, the company has achieved good sensitivity for the test using viral RNA. An initial validation of the test with samples in China is expected to wrap up within the next two weeks, and then the firm will begin a collaboration with the department of pulmonary medicine at Peking University First Hospital in Beijing to test patient specimens.
Meantime, the firm's molecular flu test could also be used as a "rule-in, rule-out" assay, to triage patients who may have coronavirus to additional testing.
Mesa is pursuing Emergency Use Authorization in China and in the US in parallel, Cai said, adding that in the US, the firm has already completed the pre-submission of its clinical study plan. The ultimate test will be deployable outside a central lab, but will not necessarily be CLIA waived. Although the assay is similar to the firm's CLIA-waived flu tests, a decision about CLIA waiver is ultimately up to regulators, company officials noted.
"The focus is to be deployable outside of the centralized lab setting," said Stephen Sepulveda, Mesa's vice president of global business.
For CLIA waiver of a device, the US Food and Drug Administration requires a number of different studies. "You need to do a lot of reproducibility and usability studies, and flex studies, and we don't know if FDA would require us to do those [for EUA], but we are in close communication with them," Cai said.
Molecular diagnostic testing offers the advantage of high sensitivity and specificity. Point-of-care testing, meanwhile, brings the diagnostics out of the lab and closer to the patient, and CLIA waiver means the test is low-complexity, so that it does not require the users have expertise in performing lab techniques.
There are a handful of other CLIA waived molecular diagnostic systems in the US, and all of them have a menu of assays that includes influenza types A and B and respiratory syncytial virus, with a few also supporting Strep A testing.
These CLIA waived molecular systems include the Roche Liat and the Abbott IDnow. The Cepheid GeneXpert Xpress and BioFire FilmArray are also been included in this list, as they are CLIA-waived tests, but the size of the instruments make them more near-patient than point-of-care.
Mesa's test system has some features that set it apart from the others. The Abbott system, which was formerly the Alere i runs isothermal nucleic acid amplification. However, like the BioFire Diagnostic, Cepheid, and Roche systems, the Mesa system runs true PCR reactions. In addition, the Mesa system has a visual read-out, much like a standard immunoassay test.
To date, the only other firm with a CLIA-waived molecular system that has publicly said it is developing a SARS-CoV-2 test is BioFire.
Mesa distributes its point-of-care system in the US through an exclusive distributor agreement with Sekisui Diagnostics. Outside of the US, the system is branded Accula, and inside the US it is branded Silaris by Sekisui, although the branding specifies that it is "powered by Mesa Biotech."
The system is intended to be as easy to use and familiar to technicians as immunoassay-based testing, with a low cost of instrumentation.
The firm began the development of its handheld system in 2014. It received CE mark for its influenza A/B test in January 2018, and FDA clearance and CLIA waiver a few weeks later. The influenza test can produce laboratory-quality molecular results in approximately 30 minutes.
Sepulveda noted that Sekisui works with major distributors like Cardinal Health, Thermo Fisher Scientific, and McKesson.
Mesa landed $23 million in financing in 2018 that it used to expand its manufacturing footprint and test menu. It's RSV test was subsequently CE marked, FDA cleared and CLIA waived. It has also expanded its manufacturing footprint in San Diego.
In addition to the SARS-CoV-2 test, Mesa is working on a Strep A assay for its system. Sepulveda said that this year was the firm's true launch season for flu and RSV, and it has seen a jump in end-user accounts in the physician office lab space in particular this season. He added that there has been traction particularly with accounts that have previously relied on visually read lateral flow tests. The instrument is also supplied at no cost to the end user and Sepulveda said the consumables are low-cost but are molecular tests so are reimbursed at a higher rate than immunoassays.
A number of other firms have described the development of coronavirus testing at the point of care of for near-patient use, as previously reported. These include tests from Cepheid, MolBio Diagnostics, Hibergene, Coyote Bioscience, and Mobidiag.
The Foundation for Innovative New Diagnostics has also curated a list, which includes tests that are commercially available to some degree globally and others that are under development.
Specifically, tests considered to be near-patient or point of care that are commercially available according to the FIND list include ones from Beijing Microread Genetics, Biomeme, CapitalBio Technology, Credo Diagnostics Biomedical, GenMark Diagnostics, Qiagen, Qingdao Jianma Gene Technology, Randox, and Selfdiagnostics. In-development tests include ones from BioFire Defense, Caspr Biotech, Diagnostics for the Real World, and QuantuMDx.