FDA grants emergency approval for antibody treatment.

Regeneron’s therapy is second of its kind to be given approval

The Food and Drug Administration on Saturday granted emergency authorization to the experimental antibody treatment given to President Donald Trump last month when he developed COVID-19, the disease caused by the coronavirus.

The drug, made by Regeneron Pharmaceuticals, is designed to prevent infected people from developing severe illness. Instead of waiting for the body to develop its own protective immune response, the drug imitates the body’s natural defenses. It is the second drug of this type — called a monoclonal antibody — to be cleared for COVID-19. The FDA authorized Eli Lilly & Co.’s drug on Nov. 9.

Regeneron’s drug is a cocktail of two monoclonal antibodies, called casirivimab and imdevimab. The FDA said in authorizing the cocktail that the drugs may be effective treating mild to moderate COVID-19 in adults and children ages 12 or older, and are indicated for those at high risk of developing severe illness. Doctors hope the drugs will keep those patients from being hospitalized.

But as with the Lilly treatment, the Regeneron drug is a biological product that is complicated and time-consuming to make; initially, it will be in short supply. The shortages, coupled with the complexities of administering the intravenous medication, have raised concerns about whether people with the greatest need will be able to get it.

Regeneron executives said at its earnings call in early November that the company projects having enough doses for 80,000 patients by the end of November and 300,000 total doses by the end of January.

Trump received an infusion of Regeneron’s investigational drug — a cocktail of two antibodies — on Oct. 2 after he was diagnosed with COVID-19 and began showing symptoms. He received the drug through a compassionate use program, also called expanded access, that allows people to get unapproved drugs. Chris Christie, the former Republican governor of New Jersey who also had COVID-19, received access to the Lilly drug, called bamlanivimab.

In tweets and videos after he was released from the hospital, Trump inaccurately described the Regeneron drug as a cure and pressed the FDA to quickly clear the medication. It was several weeks, however, before the agency took action.

Monoclonal antibodies, which are concocted in laboratories, are proteins that mimic the immune system’s ability to attack the virus. Regeneron’s COVID-19 drug is manufactured in cells from genetically engineered hamster cells.

The progress on monoclonal antibodies comes as pharmaceutical and biotech companies are racing to produce coronavirus vaccines. Pfizer and Moderna might get emergency clearance for their vaccines by year’s end; Pfizer applied for FDA authorization on Friday. But it will take months to vaccinate the population of the United States, much less the world, and the shots may not work for everyone. In any case, antibody treatments can play an important role in making the disease less dangerous.

If the pandemic keeps raging, however, there won’t be enough of the antibody treatments for everyone who might benefit from them. Unlike conventional pills, these drugs are synthesized by living organisms in specialized reactors, at a biological pace that can’t be rushed. A worldwide scramble to find capacity to make the drugs is under way, with companies striking deals with competitors to increase their manufacturing capabilities.