The U.S. Food and Drug Administration (FDA) issued an emergency use authorization on Dec. 8 for an AstraZeneca COVID-19 antibody drug designed to help prevent infection in people with compromised immune systems.
The drug, Evusheld, is a combination of two long-acting synthetic antibodies: tixagevimab and cilgavimab, which are derived from B-cells donated by patients who have recovered from the SARS-CoV-2 virus. It’s the first antibody therapy authorized in the United States for preventative COVID-19 treatment.
Both of the antibodies work by mimicking the immune system’s ability to fight the virus. They’re specifically designed to act against the spike protein of SARS-CoV-2, blocking the virus’s attachment and entry into human cells.
Evusheld, formerly known as AZD7442, is only authorized for use in individuals who aren’t currently infected with COVID-19 and who haven’t been recently exposed to an individual infected with the virus.
“Based on the FDA’s review of the totality of the scientific evidence available, the agency has determined that it is reasonable to believe that Evusheld may be effective for use as pre-exposure prevention in certain adults and pediatric individuals,” the agency said in a statement.
It has been authorized for use specifically in adults and adolescents aged 12 and older who weigh 40 kilograms (about 88 pounds) or more with moderately to severely compromised immune systems, either due to a medical condition or immunosuppressive medications. Such medical conditions and treatments include blood cancer patients, organ transplant recipients, those with advanced or untreated HIV infection, and people taking immunosuppressive drugs for conditions such as rheumatoid arthritis, among others.
The treatment can also be administered to individuals for whom COVID-19 vaccinations aren’t recommended, such as those who have a history of severe adverse reactions to COVID-19 vaccines, according to the FDA.
Evusheld will be given as two intramuscular injections, one immediately after the other. The treatment may provide up to six months of pre-exposure prevention, the FDA stated.
Preliminary data from trials show a reduction of 77 percent at primary analysis and of 83 percent at median six-month analysis in the risk of developing symptomatic COVID-19, compared to those who took a placebo.
While trials are still continuing, those who have received the shot generally have tolerated it well. However, side effects include hypersensitivity reactions, bleeding at the injection site, headache, fatigue, and cough. While infrequent, serious cardiac adverse events, such as heart failure were noted, officials said such reactions occurred in individuals who had a history of or had a risk factor for cardiovascular disease.
Both the FDA and AstraZeneca stated that the new drug is only for use in those individuals who are immunocompromised or for whom COVID-19 vaccination isn’t recommended. They stated that the injection drug isn’t a substitute for vaccination for individuals for whom the COVID-19 vaccines are recommended.
The FDA stated that it has determined that the “known and potential benefits of Evusheld, when used consistent with the terms and conditions of the authorization, outweigh the known and potential risks of the product,” noting that there are currently no such “adequate, approved, and available alternatives” on the market.
In a statement, AstraZeneca said the first doses of the drug are expected to become available “very soon.” However, the company didn’t provide a specific date.
The British–Swedish pharmaceutical and biotechnology company noted that roughly 2 percent of the global population is considered to be at increased risk of an inadequate response to the current COVID-19 vaccines that are available, while around 7 million people in the United States are immunocompromised and may benefit from the treatment.
“We are proud to play a leading role in fighting the COVID-19 pandemic and, with Evusheld, we now have the first antibody therapy authorized in the U.S. to prevent COVID-19 symptoms before virus exposure, while also providing long-lasting protection with a single dose,” said Mene Pangalos, executive vice president of AstraZeneca’s BioPharmaceuticals R&D.
Effectiveness Against Omicron
Pangalos said the pharmaceuticals company is still looking into if and how the new treatment may help fight against the new Omicron variant of COVID-19.
“Evusheld neutralizes all previous SARs-CoV-2 variants to date, and we are working quickly to establish its efficacy against the new Omicron variant,” he said. “We thank our clinical trial participants, the investigators, scientists, and government agencies, and our colleagues at AstraZeneca who have all contributed to the development of Evusheld.”
AstraZeneca has agreed to supply 700,000 doses of Evusheld to the United States.