Regeneron says it has applied to the US Food and Drug Administration for emergency use authorization for its experimental monoclonal antibody therapy, the same antibody cocktail given to President Donald Trump Friday after he was diagnosed with the virus.
The biotechnology company confirmed it had submitted the application for the authorization in a statement on its website Wednesday night.
"Under our agreement with the U.S. government for the initial doses of REGN-COV2, if an EUA is granted the government has committed to making these doses available to the American people at no cost and would be responsible for their distribution," the statement said. "At this time, there are doses available for approximately 50,000 patients, and we expect to have doses available for 300,000 patients in total within the next few months.
Regeneron's experimental antibody treatment is still in large-scale clinical trials, but has been available for compassionate use, something the FDA has to approve on an individual basis, like it did for the President.
The antibody therapy is a combination of two monoclonal antibodies that is designed specifically to block infectivity of SARS-CoV-2, the virus that causes Covid-19, according to the company's statement.
A cocktail antibody therapy uses two or more lab-engineered antibodies. Regeneron's cocktail includes a monoclonal antibody that targets the spike protein the virus uses to drill into healthy cells, and another antibody that targets a different part of the novel coronavirus. With two, the hope is to trap and shut down viral replication.
"When you weigh the potential benefit versus the risks, the downsides are very low here because we have not seen any safety concerns," Regeneron CEO Dr. Leonard Schleifer told CNN in an interview after Trump received an 8 gram dose of the treatment.
Early data from the company's antibody trials released recently showed it worked fairly safely with few side effects.
"This class of drugs is an extremely safe class," Schleifer said.
Dr. Richard Besser, a former acting director of the US Centers for Disease Control and Prevention who now heads the Robert Wood Johnson Foundation, said it makes sense that a treatment that gives a patient antibodies would help the immune system, but he said peer review will find any holes or pitfalls.
"I would withhold judgment on this until we see the data," Besser said. "You know these early results that keep coming out from companies in press releases strike me as being ... much more about the stock price than they are about science."
But Dr. Thomas Frieden, also a former CDC director, disagreed with Besser.
Although Regeneron's antibody therapy is unproven, it is "a promising treatment," Frieden told CNN.
"There's a report that only fewer than 300 patients have received it," he said. "It seems to be most effective early in the disease, especially before patients make antibodies of their own."
"We don't know if it'll be helpful, but it's something that is not unreasonable to try," Frieden said.
Regeneron isn't the only company working on antibody therapies for the coronavirus. There are at least 70 different antibody treatments for Covid-19 under investigation.