AstraZeneca's experimental Covid-19 drug has helped cut the risk of severe disease or death in a late-stage study, the British drugmaker said on Monday, a boost to its efforts to develop coronavirus medicines beyond vaccines.
The drug, a cocktail of two antibodies called AZD7442, reduced the risk of severe Covid-19 or death by 50% in non-hospitalised patients who have had symptoms for seven days or less, meeting the main goal of the study.
AstraZeneca's therapy, delivered via injection, is the first of its kind to show promise both as a preventative medicine and as a treatment for Covid-19 following multiple trials. It is designed to protect people who do not have a strong enough immune response to vaccines.
"These positive results show that a convenient intramuscular dose of AZD7442 could play an important role in helping combat this devastating pandemic," Hugh Montgomery, the trial's principal investigator, said in a statement.
Similar therapies made with a class of drugs called monoclonal antibodies are being developed by Regeneron, Eli Lilly and GlaxoSmithKline with partner Vir. These therapies are approved for emergency use in the United States for treating mild to moderate Covid-19.
AstraZeneca, whose Covid-19 vaccine has been widely used globally, asked US regulators last week to grant emergency use authorisation for AZD7442 as a preventative therapy.
AstraZeneca is submitting data from various AZD7442 studies to global health regulators, a spokeswoman said on Monday.
"We'll be continuing discussions with regulators around this new data," she said of Monday's trial results.
The trial took place across 13 countries and involved more than 900 adult participants, with one half receiving AZD7442 and the rest a placebo. Full trial results will be submitted for publication in a peer-reviewed journal, AstraZeneca said.
AZD7442 contains laboratory-made antibodies designed to linger in the body for months to contain the virus in case of an infection. A vaccine, in contrast, relies on an intact immune system to develop targeted antibodies and infection-fighting cells.
"An early intervention with our antibody can give a significant reduction in progression to severe disease, with continued protection for more than six months," said Mene Pangalos, executive vice president at AstraZeneca.
While Monday's results cover the use of AZD7442 in non-hospitalised patients, a separate trial is also studying its use as a treatment for hospitalised Covid-19 patients.
Other antibody cocktail treatments for Covid-19 have shown varied degrees of success.
Regeneron's therapy showed 72% protection against symptomatic infection in the first week, and 93% after that. GSK-Vir's showed a 79% reduction in the risk of hospitalisation or death due to any cause, while Lilly's therapy showed a 70% reduction in viral load at day seven compared to a placebo.