- The Food and Drug Administration on Wednesday authorized an antibody treatment for COVID-19 that's meant to give people who can't receive a vaccine, or whose immune systems don't respond to one, months of protection from disease.
- The drug, a combination of two synthetic antibodies developed by AstraZeneca, is cleared for preventive use prior to exposure to infected individuals. Other antibodies from Regeneron and Eli Lilly are used to treat people already infected or who were recently around others with COVID-19, such as household members.
- “Vaccines have proven to be the best defense available against COVID-19," Patrizia Cavazzoni, head of the FDA office that reviews new drugs, in a Wednesday statement. "However, there are certain immune compromised individuals who may not mount an adequate immune response to COVID-19 vaccination, or those who have a history of severe adverse reactions to a COVID-19 vaccine and therefore cannot receive one and need an alternative prevention option."
AstraZeneca's drug, called Evusheld, is the fifth COVID-19 antibody treatment authorized by the FDA, and the fourth now available after Lilly pulled one of its two medicines from the market earlier this year.
But Evusheld could still play a role because of the unique way it's meant to be used. Pre-exposure prophylaxis, as it's known, can give people who don't respond well to vaccination a treatment option that offers some protection.
Importantly, the FDA's authorization is limited to only those people who are moderately to severely immunocompromised, or allergic to a component in one of the available vaccines. Evusheld is not, the FDA warned, a replacement or equivalent substitute for vaccination in individuals for whom one of the three shots available in the U.S. is recommended.
AstraZeneca, which also developed a coronavirus vaccine used widely in Europe, tested Evusheld in a clinical trial of adults older than 59 or who had certain medical conditions. Nearly 3,500 people received the antibody treatment in the study, versus 1,731 who were given placebo.
Results showed Evusheld reduced the risk of developing COVID-19 by 77% versus placebo, and that benefit was maintained through six months, the FDA said.
Side effects to Evusheld included hypersentivity to treatment, bleeding at the injection site, headache, fatigue and cough.
The FDA also noted that more study volunteers given AstraZeneca's drug experienced serious cardiovascular events, like a heart attack or stroke, than those on placebo. Events overall were infrequent, and all participants who experienced one were at risk for or had heart disease. The FDA said it couldn't determine whether Evusheld caused the events.
When used as a treatment for mild or moderate COVID-19, AstraZeneca's two antibodies reduced the risk of hospitalization or death by 50% overall, results from a separate clinical trial showed. Regeneron, Lilly and Vir Biotechnology showed higher efficacy for their respective antibodies as COVID-19 treatments, although comparing across trials can be misleading.
In a third, earlier study of AstraZeneca's drug, treatment after exposure to infected individuals didn't significantly lower the risk of COVID-19 versus placebo, although additional analyses seemed to show it worked better in people who weren't already infected at the trial's start.
The U.S. government helped fund development of Evusheld, committing nearly three quarters of a billion dollars to late-stage testing, manfuacturing and supply of the treatment. AstraZeneca said Wednesday it has agreed to supply the U.S. with 700,000 doses, which the federal government plans to make available at no cost to U.S. residents.
In a statement, AstraZeneca said it was evaluating Evusheld against the newly identified omicron variant, but noted previous testing of some omicron mutations haven't been associated with escape from antibody neutralization. Regeneron has warned Omicron may threaten the potency of its antibody, though Vir said its treatment may hold up.
AstraZeneca originally licensed the the two antibodies that make up Evusheld from Vanderbilt University in June 2020.