The Food and Drug Administration has cleared the first cocktail of injectable monoclonal antibodies for the long-term prevention of Covid-19 in people with weakened immune systems before being exposed to the coronavirus.
The FDA on Wednesday issued emergency use authorization for AstraZeneca’s antibody cocktail, Evusheld, for what’s called pre-exposure prophylaxis, or PrEP, against Covid-19.
To date, these lab-produced antibodies have only been authorized as early treatment for Covid-19 or as preventative therapy for people at high risk immediately after close contact with a person who tests positive.
Evusheld can be used as PrEP by people 12 years of age and older who are moderately to severely immunosuppressed and may not obtain adequate immune responses from a Covid vaccine. Therapy is also an option for those rare people who have a history of serious adverse reactions to a Covid vaccine or its components.
AstraZeneca therapy involves receiving preventive injections as often as every six months. According to a large, placebo-controlled clinical trial, the cocktail is about 83 percent effective in preventing symptomatic illness during such an interval.
It is not known how the highly mutated omicron variant of the coronavirus – which is spread to 57 countries, including the United States – could affect the effectiveness of monoclonal antibody therapy.
AstraZeneca scientists are testing Evusheld against the new variant, said Ruud Dobber, executive vice president and chairman of the company’s BioPharmaceuticals business unit. They are optimistic about its effectiveness against the omicron variant because the two antibodies in the cocktail, tixagevimab and cilgavimab, target the virus spike protein in different and complementary ways.
Data is expected in the coming weeks, Dobber said in a statement.
Yet for many of the estimated 3 percent of immunocompromised American adults, the long-awaited news that the PrEP antibody has finally been eliminated should bring profound relief.
“This new FDA clearance is a very important development for people with compromised immune systems,” said Dr. Alfred Kim, rheumatologist at Washington University in St. Louis.
Evusheld like PrEP, he said, “provides a healthy antibody load for the 40 to 80 percent of immunocompromised who have very low antibody responses after vaccination against SARS-CoV-2.”
Immunosuppression is associated with a much higher risk of coronavirus infections and severe Covid. Even after vaccination, many people – including transplant recipients and those treated for cancer or autoimmune diseases – have had to stay in isolation to protect themselves against Covid.
Janet Handal, 70, a transplant recipient from New York City, runs a Facebook patient advocacy group for other immunocompromised people that has nearly 900 members. Handal, hoping Evusheld will prove to be potent against the omicron variant, said PrEP would be transformative for members of his group.
“We can come back to life. We can join our families. We can kiss someone without fear, ”she said.
Lucy Horton, an infectious disease specialist at the University of California, San Diego, said that Evusheld as PrEP may provide an extra layer of protection for the vaccinated and vulnerable, but that it “should not be taken for granted. an alternative or replacement of the vaccine. ”
PrEP candidates must test negative for the coronavirus. They must also not have been recently exposed to infected people.
In the large clinical trial of Evusheld as PrEP, which has not yet been peer reviewed, nearly 5,200 initially unvaccinated participants in the United States and Western Europe were randomized 2: 1 to receive an single injection of Evusheld or a placebo. After a median follow-up of six months, the antibody injection reduced the risk of symptomatic Covid-19 by 83% compared to placebo, AstraZeneca said.
There were no cases of severe Covid-19 or disease-related death among those who received the antibody injection, compared to five severe cases and two of those deaths in the placebo group.
Study participants are scheduled for 15 months of follow-up.
Seventy-five percent of the participants had health conditions that put them at risk for severe Covid, such as diabetes or obesity. Although only 3% are immunocompromised, experts have always expressed confidence that Evusheld as PrEP should be safe and no less effective in these people.
The federal government has an agreement with AstraZeneca to purchase 700,000 doses of Evusheld, which will be available free of charge to eligible patients. The first doses should be available “very soon”, with all doses delivered in a few months, Dobber said.
Although the drug is free for patients, healthcare facilities can charge for its administration, so people could still incur additional costs.