AstraZeneca Seeks F.D.A. Approval for Covid Antibody Treatment

AstraZeneca said on Tuesday that it had asked the Food and Drug Administration to grant emergency authorization for an antibody treatment to prevent Covid-19 in people who are at high risk of the disease. If authorized, it would become the first such preventive treatment to be available in the United States, the company said.

The company said in a statement that the treatment had reduced the risk of symptomatic Covid-19 by 77 percent in a trial in which most participants either had other medical conditions that placed them at greater risk of severe illness or were not producing sufficient antibodies after vaccination.

It said the treatment could be used in conjunction with vaccines in people with weaker immune systems. Other antibody treatments in use in the United States, including one developed by the drug maker Regeneron, have mainly been used to treat people who are already infected with the coronavirus.

“Vulnerable populations such as the immunocompromised often aren’t able to mount a protective response following vaccination and continue to be at risk of developing Covid-19,” Mene Pangalos, an executive vice president at AstraZeneca, said in a statement. “With this first global regulatory filing, we are one step closer to providing an additional option to help protect against Covid-19 alongside vaccines.”

An F.D.A. authorization would raise the fortunes of AstraZeneca, whose coronavirus vaccine, which is in use in numerous countries, has not been authorized in the United States.

Antibody treatments have gained greater attention in recent months as an alternative, if expensive, tool against Covid-19 in the United States, particularly by some who have shunned vaccines. The Biden administration has emphasized that vaccinations are the best way to prevent the spread of the coronavirus, but has urged state and local health officials to make antibody therapy — which the federal government covers at a per-dose cost of roughly $2,100 — more widely available.

The AstraZeneca treatment is one of several in a class of therapies known as monoclonal antibodies, which introduce lab-made, disease-fighting proteins into the bodies of patients, usually through an infusion.

Last month, a World Health Organization panel endorsed the use of Regeneron’s antibody treatment in high-risk Covid-19 patients, while the health agency urged the company and its partner, the Swiss manufacturer Roche, to lower the cost of the therapy and make it more widely available.