NEW YORK – Diagnostic firm Veravas is developing a high-throughput antigen test for SARS-Cov-2 detection, along with a quantitative serology test for the virus that it plans to offer to support vaccine development and vaccine effectiveness testing.
The Charleston, South Carolina-based firm is applying its sample prep technology along with antibody technology licensed from Swedish antibody firm Vicunab AB to develop the tests, which it plans to launch within the next few months.
The company is in the process of planning a pair of prospective clinical studies for an antigen test designed to diagnose infection in symptomatic patients and plans to follow that with a prospective study of the test in asymptomatic patients, said Joshua Soldo, Veravas's chief scientific officer.
The test is an agglutination assay that targets the virus' receptor-binding domain. Soldo said that the antibody that the company licensed from Vicunab AB is able to recognize the RBD in both of its primary conformations, which he said improves the test's performance. Soldo also said the company had found that the test worked better with an oral rinse sample as opposed to a saliva sample.
"The problem is that the virus is not necessarily concentrated in saliva," he said. "It's in the cheek, it's in the tongue, it's in the back of the throat."
An oral rinse sample, in which subjects swish a saline solution around their mouth, does a better job of collecting virus present in the oral cavity and throat, Soldo said.
According to Veravas, initial tests have found that its antigen test is able to detect virus in PCR-positive samples with Ct values as high as 37, indicating a very small amount of virus present. The test reports results in 10 minutes and an automated 96-well plate imaging system can run around 2,000 assays per hour. The company said it currently has capacity to produce around 30 million tests per month and that it will scale that to more than 100 million per month by January 2021.
Veravas is currently pursuing commercialization of the test through two routes — making the required reagents available for CLIA facilities to develop and run the test as a laboratory-developed test; and preparing a submission to the US Food and Drug Administration for Emergency Use Authorization for the test, either on its own or in collaboration with a larger partner.
Soldo said Veravas was "in the process of finalizing a partnership agreement with a multinational diagnostic company" that plans to distribute the test both in the US and internationally.
"We would basically provide them with the bulk reagents and they would kit it and sell it around the world," he said, adding that it remained to be determined whether in this case Veravas would take the test through the EUA process or its diagnostic partner would do so.
In addition to providing the test materials, Veravas also plans to sell plate readers, for use with the assay (sourced from an original equipment manufacturer), that it said will run the assay in a fully automated format with throughput of more than 1,000 tests per hour.
On the LDT side, the company's plans could be complicated by the FDA's recent announcement that it would no longer be reviewing EUA submissions for SARS-CoV-2 LDTs. While this means labs could offer the test without first taking it through the EUA process, it could negatively impact its commercial prospects, as many doctors view FDA authorization as a mark of quality.
Veravas CEO Carroll Streetman acknowledged that this could present a challenge and said that the company's pursuit of EUA for a kit version of the assay would help address it.
"We're going to [offer] RUO [components] and it is up to the labs if they want to develop laboratory-developed tests, but at the same time we are going down the path towards an EUA, and when the test is [authorized] by FDA, then those same CLIA labs can have access to the kit, as well, and avoid any issues they may be seeing with laboratory-developed tests in this space."
Soldo said the company expects to make its EUA submission in December and launch sales of the test by January 2021.
Veravas is also developing a quantitative SARS-CoV-2 serology test that Soldo said it expects will see uptake for vaccine efficacy testing. This test, in particular, he said, would benefit from Veravas's core technology, which uses inert magnetic beads to reduce interferences and non-specific binding. Essentially, the company pretreats samples with all the components of an assay, allowing each of those components to bind to any interfering molecules attracted to them. It then aspirates the remaining sample, which is now largely free of these interferences, and then runs the actual assay.
To date, the company has marketed its technology primarily for removing potentially interfering biotin from clinical samples. It has also used the technology in collaboration with proteomics firm Tymora Analytical Operations to provide sample prep to improve Tymora's measurements of circulating protein markers for diagnosing Alzheimer's disease.
Soldo said that the technology, while not part of the antigen assay, would prove useful for developing highly specific serology assays.
"We can report highly accurate and sensitive results without the impact of interferences," he said. This is particularly important for SARS-CoV-2 serology testing where tests without extremely high specificity could give large numbers of false positives due to the relatively low prevalence of the disease.
The Veravas serology assay will measure quantitative levels of antibodies against the RBD and the N-terminal domain of the SARS-CoV-2 spike protein.
Soldo said the company plans to take the serology assay through the EUA process and bring it to market early next year.