- FDA on Friday said it gave emergency use authorization to the first serology test designed to detect neutralizing antibodies in people previously infected with SARS-CoV-2.
- While neutralizing antibodies can block infection, previous EUAs during the pandemic have been issued for serology tests that screen only for the type of antibodies that do not necessarily decrease viral infection.
- The new test is from biotech GenScript, whose Hong Kong-listed shares slumped in September after the disclosure that Chinese customs was investigating the company for suspected violations of import and export regulations. GenScript is the parent of Legend Biotech, known for its partnership with Johnson & Johnson to develop a multiple myeloma treatment and whose U.S. initial public offering in June was one of the year's biggest biotech IPOs.
Antibodies that neutralize SARS-CoV-2 are being studied as one possible way to prevent infection, but the relationship to immunity is still unclear. How long antibodies persist after infection is also unknown, FDA noted in its letter to GenScript granting authorization for the cPass SARS-CoV-2 Neutralization Antibody Detection Kit. Patients should not assume immunity based on any serology test results, and the tests should not be used to diagnose a current infection, the agency stressed.
FDA said it has issued EUAs to more than 50 serology tests for detecting the presence of antibodies. The number of antibody tests issued to commercial developers has picked up pace in recent months, with 27 authorizations granted in September and October alone. The first point-of-care version of an antibody test, a product from China's Assure Tech that yields results in 15 minutes from a few drops of blood, received an EUA in late September.
Abbott, Beckman Coulter, DiaSorin, Roche, Siemens Healthcare Diagnostics, and Thermo Fisher Scientific are among the latest companies to gain EUAs for antibody tests. Abbott CEO Robert Ford told analysts on a call last month that antibody tests have not generated the level of demand that the company initially expected to see, but he predicted interest would pick up once coronavirus vaccines are rolled out.
Siemens has asserted that antibody tests are key to controlling the spread of the pandemic and may be used to help verify the effectiveness of vaccines when they become available.
Rainer Blair, CEO of Beckman Coulter's parent company Danaher, said on last month's earnings call that COVID-19 antibody tests could play a critical role both pre- and post-vaccination for population surveillance and clinical trial studies, despite their relatively limited use today.
However, the category of tests came under criticism early in the public health emergency when the agency allowed self-validated tests on the market without an EUA submission and whose accuracy subsequently came into question. Tests were also being promoted inappropriately for diagnostic use.
FDA in May revised its approach to require commercial antibody test developers to submit an EUA, though they can still distribute the tests as long as an EUA is being prepared. The agency also began pulling inaccurate tests off the market. It revoked two EUAs for antibody tests over the summer, from Autobio Diagnostics and Chembio Diagnostic Systems, after determining the products may be ineffective.