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Canary Health Technologies Continues COVID-19 Test Development With Ultra-Rapid Saliva Test

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NEW YORK – Previously using a breath-based method to develop its diagnostic tests, Canary Health Technologies is expanding its reach as a result of the COVID-19 pandemic to other sample types, using the same biosensor technology.

It has submitted its saliva-based Pelican CV-19 test and Pelican CV-19 analyzer to the US Food and Drug Administration for Emergency Use Authorization as an over-the-counter at-home test and is preparing to supply the test commercially when and if the authorization is granted. 

Although the firm began with the intent to detect lung cancer from breath, the pandemic led Canary to add a new line of development, modifying its breath sensor system that originally was used to differentiate gases signaling the presence of volatile organic compounds to measure antigens. 

Canary's proprietary technology doesn't require amplification and instead uses a digital pulse to read what the biosensor is picking up, CEO Raj Reddy said. In place of amplifying the measured protein of the virus and waiting for the signal to be high enough, Canary measures the antigen directly in the sample, which also allows it to return results in less than a minute at low concentrations, he added. The "ultra-rapid antigen test," according to Reddy, "fits the gap between low-sensitivity antigen tests and RT-PCR."

The sensor systems run a digital pulse to get a reading specific to the antigens being looked for, which in Pelican's case are the spike and nucleocapsid proteins of SARS-CoV-2. "We're targeting two proteins simultaneously, which gives us a much higher sensitivity to variants as well," Reddy said. There are two sensor systems built into the cartridge, one primed for the S protein and one for the N protein, that one digital pulse runs across, Reddy said.

By looking for two proteins and targeting two parts of the virus, there are more binding sites available and more variations can be accounted for, making the test more sensitive, he added. "If you can hit it more times, you're going to get a better sensitivity to the virus as it varies from region to region," he said.

Part of the issue with many rapid antigen tests on the market today, Reddy noted, is that their sensitivity depends on the viral load of the sample. Canary's test is sensitive for samples from symptomatic and asymptomatic people, which Anna Wang, SVP of corporate affairs and strategic partnerships, says the company knows because they looked at the results of their trials next to results from PCR tests for samples with higher cycle threshold values – signaling lower viral loads – and found the Pelican test was able to detect the virus in those samples, correlating to asymptomatic people.

Providing a saliva sample makes the test "a lot simpler … [because] most people know how to spit" Wang said. Other tests using nasal swabs require an individual to know how to swab and collect the sample, she added. Many of the other antigen tests on the market do mid-turbinate nasal swabs, which Reddy said provided a much less sensitive sample.

"One of the reasons we picked saliva is that you're getting a very accurate sample, so there's less error," Reddy said. "All of the procedures of the test are designed to be user-friendly, so that … when you're doing this type of testing it's simple, and you have less errors actually doing the test which means the results are better." The saliva collection system is built into the test's disposable cartridge, he said. 

However, there have been debates over whether saliva is actually as sensitive as nasal swabs. Early in the pandemic, the US Centers for Disease Control and Prevention did not list saliva as a recommended specimen for testing, and many companies and researchers originally shied away from saliva-based SARS-CoV-2 tests.

That being said, as the pandemic has worsened and widespread testing has become more necessary, many companies have had success with saliva-based tests, including Fluidigm and PerkinElmer. Other firms have also received reissued Emergency Use Authorizations from the US Food and Drug Administration allowing their tests to be used with saliva as a test sample.

And a literature review published in Travel Medicine and Infectious Diseases in November looked at 39 studies and found saliva samples for SARS-CoV-2 were as sensitive as nasopharyngeal swabs in most of the studies.  

Mara Aspinall, a professor of practice in biomedical diagnostics at Arizona State University's College of Health Solutions, said she was "very comfortable" calling saliva's performance as a sample type for SARS-CoV-2 tests equal with nasopharyngeal swabs "without reservation." In addition, she noted saliva "doesn't have the collection challenges" like nasopharyngeal swabs may have, since the collection process is simpler.

According to two studies from Canary, the sensitivity of the test is 98 percent, while the specificity is 100 percent. One analytical study tested 400 to 500 saliva samples while the other used 100 live samples for the FDA submission and both studies returned the same sensitivity and specificity numbers. In addition, the firm tested an asymptomatic pool of samples, and Reddy said the Pelican test "picked them all up," and noted the studies' results matched RT-PCR results. The company declined to share the studies because it is currently in discussions with the FDA.

Aspinall, who has researched Canary Health Technologies, said if the company's claims are true, it would be a "fantastic" addition to the COVID-19 testing space. However, she noted she'd like to see the data and said it was important to see "what can be proved through pilot data and real-world evidence."

The question of SARS-CoV-2 variants has been prevalent in recent months, as more strains are discovered across the world. According to Reddy, the Pelican is flexible and is able to cover more variants as they are discovered. "It would be very difficult based on our targeting system now for a variant to mutate out of what we can detect now, but let's say it did," Reddy said. "If it did, it takes us about 30 days to put down a new sensor system and get those cartridges out to market." 

He added that Canary is currently working on a molecular test that can detect whether someone is infected and which of the prevalent variants of SARS-CoV-2 someone has in less than five minutes, whether it’s the South African variant, the United Kingdom strain, or the original wild type. That test would use the same reader and cartridge system, although the digital pulse would instead target the actual gene, rather than an antigen, Reddy said.

Aspinall noted that all current antigen tests on the market can detect positive results accurately even with current SARS-CoV-2 variants, so Canary's claim may not be particularly unique. "This is because antigen tests are focused on the N protein and all the mutations of current concern are on the spike protein," she said. 

Another issue Reddy mentioned is the time to result of many rapid antigen tests on the market, some of which take up to 20 minutes. Canary's test, because it uses a digital pulse rather than amplification and fluorescence like in a lateral flow test, can return results within 30 seconds, Reddy said.

In addition, many of the antigen tests on the market have results read by the eye, which makes them prone to errors in interpretation. Canary's reusable reader has a screen that scans the result, acting as a "self-diagnostic safeguard" to note if there's any issue with the test running properly, Reddy said. 

Tying into the digital aspect of the test, Wang noted the connectivity capabilities of the test. Each cartridge has a QR code that can be scanned, and the result from the cartridge shows up on a user's phone with Canary's mobile app. That connectivity could be essential for testing and tracing by making people's results easily accessible, Wang said. 

The reusable reader is priced at around $50, while the disposable cartridges for each test are around $25 – comparable to current home tests, Reddy said. Ellume's COVID-19 Home Test costs about $30, while Abbott's BinaxNow COVID-19 Ag Card Home Test costs $25, plus overnight shipping.

The price is meant to be achievable for the average consumer, because "these types of rapid tests need to be done three times a week" to get the pandemic under control, Reddy said. 

Aspinall, though, said COVID-19 tests would likely need to be $10 or less for the broad market to reach saturation and that instrument-free tests would likely be more in demand for the at-home market. She added that demand will continue for tests like Canary's, particularly for businesses and organizations who need to test higher volumes of people. 

Canary intends to manufacture about 50 million tests in the first year, and Wang said by the end of the first 12 months Canary plans to be making 10 million tests per month. Although it would take the company a few months to ramp up its production once it receives EUA, Reddy said it would be able to increase capacity and tooling to adjust production depending on surges or fluctuations in demand. "If the market's showing a huge need beyond what we expected, then we can start to ramp up to try to meet some of that need," Reddy said.

Canary has been working with Smartshape, a product design and development firm, to help commercialize the product and "design an effective user experience," CEO Mike Maczuzak said. Smartshape has helped manufacture units for the test trials, although it will not be in charge of the full-scale manufacturing if the test is authorized for use.

Maczuzak is also an investor in Canary and said the benefits of the test are that it is small and returns results quickly compared to large equipment in central laboratories. The only challenge, he said, was figuring out how to get the test to mass producible numbers and how to quickly manufacture "tens of millions" of units. 

Currently, the firm is manufacturing products in house for clinical trial production, Wang added, but once commercialization begins in earnest the manufacturing will be outsourced to a contract manufacturing partner in the US.

To distribute the test, the plan is to work with buyers and distributors, such as hotel chains and airlines, who will buy the tests in bulk, although the firm has also been in contact with the United Nations and has made contact with the White House's COVID-19 Task Force about providing its tests, Wang said. Reddy said buyers have committed to purchasing 20 million of Canary's test.

In addition to FDA EUA, the firm is also planning to submit its test and device for CE marking in the next two weeks and is expecting that approval in March for point-of-care use with a professional. Reddy said the company may submit its test to Health Canada as well but noted the US and Europe will likely take up much of the manufacturing capacity. 

Reddy was quick to note that the firm is not giving up on its breath testing background and is continuing to develop its breath-based COVID-19 test, which is currently undergoing trials in India. That test looks for the metabolic response to SARS-CoV-2, specifically a unique VOC signature correlating to COVID-19, detecting breath biomarkers using gas sensors that convert the VOC molecules to digital signal patterns.