The FDA authorized use of a COVID-19 semi-quantitative antibody testing kit that appears to detect the exact level of IgG antibodies to SARS-CoV-2, test manufacturer Kantaro Biosciences announced on Wednesday.
COVID-SeroKlir received emergency use authorization (EUA) for the assay, which detects SARS-CoV-2-specific IgG antibodies against the full length spike protein and its receptor binding domain with 98.8% sensitivity and 99.6% specificity, Kantaro said. It is described as a two-step enzyme-linked immunoassay that can be used by any CLIA-certified laboratory with no proprietary equipment needed.
Measuring IgG antibody levels is useful not only for informing healthcare decision-making, but public health strategies and assessing vaccine response, the company added.
“Having a numerical understanding of antibody levels can be especially powerful for patients, enabling them to take control of their health and enjoy some peace of mind during these uncertain times,” Kantaro’s chief commercial officer, Sara Barrington, said in a statement.
The test’s EUA documentation had not yet been made public by the FDA on Wednesday. Stipulations for previous SARS-CoV-2 serology tests receiving EUAs had included a caution that an individual’s results “cannot be interpreted as an indication of degree of immunity or protection from reinfection.”
Kantaro is a joint venture between New York City’s Mount Sinai Health System and RenalytixAI. It was formed as a way to develop, produce, and distribute the testing kit based on the serological assay at Mount Sinai, which was partially developed by Florian Krammer, PhD, of the Icahn School of Medicine there.
The technology was developed and validated based on over 80,000 patient samples. Recently published data from an ongoing study that used the test found that most people with COVID-19 mount an antibody response that remains stable at least five months following infection.
Kantaro partnered with Bio-Techne Corporation, who will help to manufacture the tests, with a capacity of up to 10 million tests per month and the ability to scale up to produce more.
The testing kit received the CE mark in October 2020 and is available in 29 European countries, Kantaro said.