The US Food and Drug Administration (FDA) revised its emergency use authorization (EUA) for COVID-19 convalescent plasma to limit its use to high titer units and only in hospitalized patients who are in the early stages of the disease or who have impaired humoral immunity.
Convalescent plasma emerged as a potential treatment for COVID-19 in the early months of the pandemic. Initially, FDA facilitated its use through single patient emergency investigational new drug applications (eINDs) in March 2020 before signing off on a large expanded access protocol led by the Mayo Clinic that provided transfusions to 94,000 patients.
The move to restrict the treatment’s use comes six months after the agency’s controversial decision to authorize convalescent plasma, under pressure from former President Donald Trump, based on limited evidence and amid reports that the EUA was on hold after top National Institutes of Health officials raised concerns about the strength of evidence available at the time.
“Issuance of, and updates to, EUAs are based on a thorough evaluation of currently available scientific evidence about medical products. In this case, as additional scientific evidence about COVID-19 convalescent plasma emerged, we revised the EUA to reflect the updated evidence. COVID-19 convalescent plasma used according to the revised EUA may have efficacy and its known and potential benefits outweigh its known and potential risks,” FDA’s Center for Biologics Evaluation and Research Director Peter Marks said in a statement.
According to the revised letter of authorization and decision memorandum for convalescent plasma, additional data from randomized controlled trials and observational studies have hinted that high titer plasma administered early in the humoral immune response may be effective. However, the letter of authorization still stresses that “COVID-19 convalescent plasma should not be considered a new standard of care for the treatment of patients with COVID-19,” and that ongoing clinical trials investigating the use of convalescent plasma should not be amended based on the updated EUA.
In addition to restricting the use of convalescent plasma under the EUA to high titer units and earlier on in the course of disease, FDA added seven SARS-CoV2 IgG tests from Abbott, Beckman Coulter, Euroimmun, GenScript, Kantaro, Roche and Siemens to the list of acceptable tests for quantifying high titer COVID-19 convalescent plasma.