We have all heard the stories of long wait times for COVID-19 test results, and many of us have experienced it directly. Test samples that would normally return results in a day or two need to be sent to overworked laboratories and come back in five or ten days instead. By that time, of course, the result is nearly moot. The infection may have run its course, or the person awaiting confirmation may have needlessly quarantined herself only to find out her test was negative. The tests involved here are the highly accurate and sensitive PCR assays, the gold standard ones that require the invasive, deep nasal swabs we’ve all heard about.
Now there are some fast-response antigen tests available, including the well-known Abbott BinaxNOW antigen test that is being distributed, to various effect, in the US by the federal government. The fast-response tests that have been approved so far are designed primarily to test symptomatic patients and require a medical professional to administer them, utilizing nasal samples. They aren’t quite as sensitive and accurate as the PCR tests, but places like the Philippines and Italy are using them to screen people like incoming travelers and symptomatic patients in their first week.
What is missing from the current picture is the equivalent of the at-home pregnancy test – something that can be administered without a medical professional, that doesn’t require a nasal swab, that can be scaled without encountering the supply chain and lab-delay problems inherent in the current testing regime. One company, Therma Bright, Inc. (TSXV: THRM), thinks it is homing in on a saliva-based test that could check all of these boxes, pending regulatory approval.
Therma Bright’s Potential Solution
Therma Bright makes and markets medical devices to treat conditions like cold sores and insect bites. In August of 2020 the company began a partnership with Orpheus Medica, a privately held Canadian biotech company, to develop a saliva-based test called CoviSafe™ for COVID-19 antigens that is accurate, convenient, and doesn’t rely on reagents that are in short supply. Therma Bright gave a progress report shortly thereafter, indicating they had identified “several high-quality polypeptides that recognize the COVID-19 virus with clear distinction from other coronavirus types such as SARS or MERS.”
Matching the urgent timeline caused by the pandemic, Therma Bright announced in late October the successful completion of feasibility studies and the engagement of nanoComposix Inc. to provide the appropriate nanoparticles and assay materials for the CoviSafe™ test. The next step is to take the most promising molecules from the laboratory-based feasibility studies, those that demonstrated the highest levels of sensitivity and specificity for the detection of COVID-19 antigens, and apply them in field tests to assess their accuracy and viability.
In anticipation of the fast-approaching commercialization phase, Therma Bright created in early November a new joint venture called Torion Biosciences Inc. Therma Bright has a 50% controlling interest in the new entity, which is essentially an outgrowth of the successful joint development arrangement with Orpheus Medica. Torion will be the vehicle for the regulatory approval and product rollout initiatives, building upon the successful lab work of the previous partnership.
What’s the Plan?
Initially, Therma Bright is looking to get the tests approved through Emergency Use Authorization in Canada, Europe, and the United States for the testing of symptomatic patients, overseen by health care professionals. US Food and Drug Administration (FDA) baseline requirements for such approvals consist of 80% minimum accuracy in the testing of 250 symptomatic patients, with the CoviSafe™ results checked against PCR test results to confirm both positive and negative results.
That is the first step in the regulatory approval process, and Therma Bright anticipates achieving that step in the next several weeks. If, as anticipated, CoviSafe™ meets those benchmarks, Therma Bright will immediately seek expedited approval with the FDA, Health Canada, and European Union regulators. The FDA has authorized only seven such antigen tests to date, as compared to the 189 PCR tests and the 58 antibody assays confirmed by the agency.
This is not the endgame for Therma Bright however. The company is wholly invested in providing CoviSafe™ as a screening test for asymptomatic people as well. The goal is to provide for routine and widespread testing in homes, schools, workplaces, and events. This is the use that could be a game changer in the struggle to contain the spread of COVID-19. According to US Centers for Disease Control (CDC) estimates:
- about 40% of infections are asymptomatic,
- asymptomatic people are about 75% as infectious as symptomatic patients,
- about 50% of transmission occurs prior to symptom onset.
Clearly, it is essential to catch cases before the presentation of symptoms in COVID carriers. Antibody tests can’t achieve this goal because antibodies are not generally detectable until several days after the onset of symptoms, and may not be detectable at all in asymptomatic people. PCR tests can accurately test for COVID in asymptomatic individuals but test results are often delayed past the point of utility. PCR tests also detect very small bits of viral genetic material, meaning they can return positive tests long after the patient is infectious. At this point, only rapid antigen tests can hit the sweet spot of early, accurate detection combined with timely results.
Therma Bright believes it is on the right track to provide early, rapid, accurate detection of asymptomatic and presymptomatic COVID-19 cases. With 40% of cases being asymptomatic and about 50% of virus spread occurring prior to symptoms, the lack of this type detection is one of the biggest hurdles to limiting the spread of the highly infectious disease. “We think antigen tests have the greatest potential for screening asymptomatic people,” said Mara Aspinall, MBA, cofounder of the Biomedical Diagnostics program at Arizona State University and a contributor to The Rockefeller Foundation’s COVID-19 National Testing & Tracing Action Plan.
Therma Bright is certainly on the fast track with its efforts and anticipates major developments in the coming weeks. Keep an eye out for announcements as the company executes its approval and commercialization plans.