A New, Simple, On-Site Test for Detection of and Prevention from SARS CoV Viruses

In this Phase II SBIR, Mesa Photonics proposes to clinically validate its new test system for detecting SARS coronaviruses. The test uses a tongue scrape sample as a specimen that is easily and painlessly collected by subjects themselves. A simple response, positive or negative, is produced in < 15 minutes in an existing, portable, battery-operated handheld fluorometer. The test measures the activity of a SARS coronavirus enzyme in infected cells. The enzyme is a protease that cleaves a four amino acid protein fragment (tetrapeptide) that releases fluorescence when it is cleaved. Another peptide is used as a positive control and fluoresces when it is cleaved by Angiotensin Converting Enzyme 2 (ACE2). In Phase I we show that the fluorescence of both peptides can be read simultaneously in one sample. The SARS tetrapeptide is reportedly cleaved only by SARS-CoV-1 and SARS-CoV-2 and not by MERS. In Phase I, we show that it is also not cleaved by human proteases present in active tongue scrape lysate or by proteases from three other coronaviruses. A detection limit of ~15,000 229E coronaviruses in <6,000 infected human cells was determined using the substrate ISG15 that contains the natural tetrapeptide amino acid sequence on which our specificity-conferring tetrapeptide is based. A Phase II goal is to combine the specificity and sensitivity-conferring sequences into a novel proprietary substrate. The sensitivity of the test is expected to easily allow detection of the 3 million to 30 million SARS viruses anticipated to be present in infected epidermal cells of the tongue. The Phase II work will validate and compare the performance of the test system in clinical samples from subjects who tested positive or negative with RT-PCR. Next, Emergency Use Authorization (EUA) and dual 510(k) clearance and a CLIA waiver will be obtained. Mesa Photonics will engineer a multi-sample prototype tester based on the Phase I design specifications that can measure 10 samples sequentially. In addition to the use of the test system as a rapid, on-site COVID-19 diagnostics tool, the test reagents will be validated as stand-alone commercial products. They are suitable for SARS protease drug screening and for directly determining the neutralizing activities of natural, therapeutic or vaccine-derived antibodies. The current invention is patent-pending and another filing is expected to result from the Phase II efforts.  The commercial product is a simple, fast, and affordable on-site test system that meets all requirements for deployment to remote locations. It is of special interest to pharmaceutical companies as a companion diagnostics assay for subjects enrolled in clinical trials in which the efficacy of COVID-19 vaccines or booster shots are determined. Following a Low Rate of Initial Production, complete test systems will be produced by our commercial partner. Complete test systems are expected to benefit both military and civilian organizations.