AstraZeneca Covid-19 Antibody Authorized by FDA as Novel Tool to Prevent Symptomatic Disease

AstraZeneca said earlier this year that it would aim the antibody combination, called AZD7442 and delivered as two consecutive shots, at preventing Covid-19 symptoms, like a vaccine. Emergency-use authorization from the FDA offers a new preventive option in addition to widely deployed vaccines.

AstraZeneca said about seven million people in the U.S. may benefit from Evusheld to reduce their risk of symptomatic Covid-19 if taken before exposure.

Monoclonal antibodies are the only drug treatments authorized for mild to moderate Covid-19 cases in people who aren’t sick enough to be hospitalized. The drugs, which are given by infusion or injection, provide a temporary substitute for the antibodies produced by the immune system to fight the virus after infection or vaccination.

AstraZeneca’s drug is the first to get U.S. clearance to prevent Covid-19 in people who aren’t yet infected, but the company could face competition in the coming months. Rivals including

Regeneron Pharmaceuticals Inc.

are also seeking authorization for drugs to temporarily defend against infection.

Regeneron said in November that its antibody drug REGEN-COV was 82% effective at preventing infection at least eight months after infusion in a study that included patients who hadn’t yet been exposed to the virus.

Pfizer Inc.

is also testing its antiviral pill Paxlovid to prevent infections in people recently exposed to the virus, which could provide another option for people with weakened immune systems.

The FDA said the authorization is for individuals not infected or recently exposed to someone infected with the virus. It said that vaccines remain “the best defense available against Covid-19.” In the agency’s statement, Patrizia Cavazzoni, director of the FDA’s Center for Drug Evaluation and Research, said that Evusheld could help reduce the risk of Covid-19 in a subset of the population with a history of adverse reactions to Covid-19 vaccines or their components or with compromised immune systems.

“Pre-exposure prevention with Evusheld is not a substitute for vaccination in individuals for whom Covid-19 vaccination is recommended,” the FDA said.

The antibody treatment is separate from AstraZeneca’s widely used Covid-19 vaccine developed in partnership with the University of Oxford. That vaccine is one of the most broadly distributed globally, with more than 2.2 billion doses delivered, but it isn’t authorized for use in the U.S.

AstraZeneca said it’s testing Evusheld against the new Omicron variant. It “neutralizes all previous SARS-CoV-2 variants to date, and we are working quickly to establish its efficacy against the new Omicron variant,” said Mene Pangalos, the company’s executive vice president for biopharmaceuticals research and development, in a statement.

Some scientists think that Omicron may have developed in a patient whose immune response was too weak to clear the virus, allowing it time to adapt and mutate. The rise of variants like Omicron highlights the need for treatments to better protect people who mount weak immune responses to the virus causing Covid-19, scientists say.

The company in August said Evusheld, also called AZD7442, showed 77% efficacy in reducing risk of symptomatic Covid-19 compared with a placebo in late-stage clinical trials testing its usefulness as a preventive treatment. In summarized preliminary findings, the company said that more than three-fourths of the 5,197 participants in the trial had comorbidities, or chronic disease, including conditions that could render vaccines less effective.

Protection has been shown to last six months, the FDA and AstraZeneca said. Evaluation of the antibody combination is ongoing.

Monoclonal antibody drugs are designed to mimic natural antibodies produced by the immune system to fight the coronavirus. AstraZeneca earlier hoped the therapy could be used to treat acute Covid-19 symptoms and stem infection to keep people already exposed to the virus out of the hospital. But the drug failed in late-stage trials for that primary purpose.

Earlier in the pandemic, AstraZeneca received funding pledges that could exceed $700 million from the U.S. government to develop, test and potentially supply up to 700,000 doses of AZD7442 this year. The antibodies used were developed by Vanderbilt University Medical Center and licensed to AstraZeneca in June 2020.

European medicines regulators are also reviewing data for potential authorization of the antibody combination.

Write to Jenny Strasburg at [email protected] and Joseph Walker at [email protected]