NEW YORK (GenomeWeb) – Having recently snagged $23 million in new financing, Mesa Biotech plans to expand its manufacturing capacity and further develop new assays for its US Food and Drug Administration-cleared point-of-care molecular diagnostic system.
The firm's handheld molecular testing instrument, called the Accula, was CE marked as well as cleared and CLIA waived by the FDA earlier this year, along with an assay for influenza that performs testing in around 30 minutes directly from nasal swabs.
Mesa Cofounder and CEO Hong Cai said that the overall design is meant to provide a user experience very similar to visually read immunoassays.
The underlying technology was originally developed at Los Alamos National Laboratory. It consists of two components; a dock and an assay-specific, disposable, cassette containing reagents. The dock is portable and lightweight. "You can really hold it in your palm, or put it in your purse," Cai said.
For the test, a user puts a sample into the cassette, places it in the dock, and closes the lid, automatically sealing the test cassette. Then the dock automatically drives the reactions through to completion, Cai said. When the assay is complete, the final readout is colorimetric, so the user just reads the line like in a familiar rapid antibody test, she said. Because the instrument is not reading the result, it is by definition not a diagnostic instrument, she added, so it does not require the support a diagnostic instrument requires in terms of calibration and maintenance.
The patented PCR method the instrument uses is an oscillating amplification reaction called OSCAR. It is almost like a hybrid between isothermal PCR and real-time PCR, using various technologies to reduce absolute temperature requirements such that there is a smaller temperature differential between the annealing and denaturing steps, oscillating over a temperature range of about 20 degrees Celsius. The method also has the added benefit of reducing cycling times. Additionally, the firm uses patented technology for lateral flow-based nucleic acid sample preparation and passive fluid flow control.
Although the method has not yet been published, the clinical trial preliminary results will be published soon in a peer-reviewed journal by Tri-Core Reference Laboratories, which carried out the testing, Cai said.
The system is likely to be less expensive than other commercially available CLIA-waived point-of-care molecular systems, said Steven Sepulveda, vice president of global business development and channel management at Mesa. This is in part because those systems require instruments that need service agreements and calibration, he said.
In April, Yale clinical researchers Marwan Azar and Marie Landry noted in a Journal of Clinical Microbiology review article that there has been a "paradigm shift," particularly in physician office labs, towards molecular flu testing that is driven in part by the FDA reclassification of rapid influenza diagnostic tests, or RIDTs, from Class I to Class II devices.
The CLIA-waived POC molecular flu space, according to that study, includes the Alere i influenza A and B test, and Alere i RSV test, the Roche Cobas Liat Influenza A/B and Influenza A/B/RSV assays, the Cepheid Xpert Xpress Flu or Flu/RSV, BioFire FilmArray Respiratory Panel EZ, and the Accula Flu A/Flu B.
These instruments reportedly cost in the range of thousands of dollars, however, while the Accula dock is in the range of hundreds of dollars, according to Sepulveda.
In addition to a potentially lower acquisition and operating cost than other waived molecular tests, the Accula has no need for instrument calibration and has minimum maintenance requirements. Sepulveda noted that, because of the low cost of the dock and small size, users can also add docks to be able to run more than one test at a time, although they will not be connected to each other.
Furthermore, neither the cassettes nor any of the components require refrigeration. This could be helpful to users because, "in physician offices, refrigeration space is at a premium," said Sepulveda.Â
Considering RIDTs continue to be the lion's share of the physician office point-of-care market, Mesa may be able to carve out a niche by combining the high sensitivity of a PCR test with the familiarity of a visually read immunoassay test, Sepulveda said.
While manufacturers of immunoassays such as Quidel and Meridian have branched into automated readers for their tests that also have increased connectivity, Sepulveda noted that more than half of immunoassay units are still visually read. "There's a place for instrumentation and connectivity," he said, but the Mesa system is unique in the POL space in that it "straddles PCR accuracy and results with the simplicity of a visually-read test."
San Diego-based Mesa formed an advisory board in 2016, and the firm partnered with IVD developer Sekisui the following year. The Sekisui relationship stipulates co-branding of the dock and tests for distribution in the US and Canada, but the exclusive partnership only covers Mesa's respiratory products, Cai noted.
Sekisui Diagnostics has since launched the Silaris Influenza A&B test, which is co-branded with Mesa and runs in 30 minutes.
With Sekisui as partner, Mesa has already loaded systems into major national distributors such as McKesson, Henry Schein, Cardinal, Thermo Fisher Scientific, and MedLine, Sepulveda said.
Flu testing is heavily promoted before the flu season starts, starting in August and September, he said, and distributors are now offering promotions for the flu season to come. A typical promotion would involve the purchase of a certain number of test cartridges – which for the flu test have an average sale price of about $30 – and then customers would get free docks to run the tests.
This lower threshold for entry may be easier to achieve for physician offices than a costlier instrument purchase or reagent rental that involve a service contract and a longer-term commitment, Sepulveda said.
Mesa has other respiratory infectious disease tests in its pipeline. The firm has completed a clinical trial for an RSV assay and expects to obtain CE mark and launch in Europe later this year. It has also already submitted a dual submission to the FDA for 510(k) clearance and CLIA-waiver for its Accula RSV test. In addition, Mesa plans in the future to expand into sexually transmitted diseases and women's health.
The firm will now use the new funding — consisting of a $20 million Series B round in July and $3 million Series A round earlier this year — to further expand manufacturing capacity and move these pipeline products forward. Specifically, Mesa has leased a new facility in San Diego dedicated to scaling up production, Cai said.
"It will give us amazing capacity to address market demand and growth for years to come," Sepulveda added.
The Series B investors wish to remain "low key" for the time being, Cai said, so she was not able to disclose their identity at this time. "Suffice it to say, we are excited because it is a major raise … and it is certainly a validation of our technology and our business to have that level of investment," Sepulveda added.
The firm has placed some systems since it obtained CE mark, FDA clearance, and CLIA waiver, but these regulatory milestones came in the middle of the previous flu season, so the upcoming season will be the its first full season, Sepulveda said.Â