FDA OKs Antibody Cocktail to Help Immune-Compromised Fend Off COVID

The U.S. Food and Drug Administration on Wednesday granted emergency approval of a new antibody cocktail to prevent COVID infection in people who have weakened immune systems or who can't tolerate COVID vaccines.

“Vaccines have proven to be the best defense available against COVID-19. 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,” Dr. Patrizia Cavazzoni, director of the FDA’s Center for Drug Evaluation and Research, said in an agency news release.

“Today’s action authorizes the use of the combination of two monoclonal antibodies to reduce the risk of developing COVID-19 in these individuals," she said.

AstraZeneca’s Evusheld (tixagevimab and cilgavimab) can now be given to certain adults and children 12 and older who weigh at least 40 kilograms (about 88 pounds).

The antibody treatment is authorized for two groups of people, including those who have moderate to severely compromised immune systems due to a medical condition or because they're taking immunosuppressive medications or treatments and may not have an adequate immune response to COVID-19 vaccines.

The other group includes people with a history of severe adverse reactions to a COVID-19 vaccine and/or component(s) of those vaccines, and therefore shouldn't get vaccinated, the FDA said.

People who could benefit from Evusheld include cancer patients, organ transplant recipients and people taking immune-suppressing drugs. Health experts estimate about 2% to 3% of the U.S. population falls into that category.

"These people still have to shelter in place because they’re at really high risk of severe disease and death," Dr. David Boulware, of the University of Minnesota, told the Associated Press ahead of the announcement. "So having this therapy will enable a lot of them to get back to their normal lives."

One dose of Evusheld is administered as two separate, consecutive injections and may be effective for six months, according to the FDA.

The approval is based on a clinical trial of adults older than 59. It found that those who received Evusheld had a 77% lower risk of COVID-19 than those who received a placebo, and the reduced risk lasted for six months.

Possible side effects of Evusheld include: hypersensitivity reactions (including anaphylaxis), bleeding at the injection site, headache, fatigue and cough.

Serious heart problems such as heart attack and heart failure were more common in the Evusheld group than in the placebo group, but it's not clear if the antibody treatment actually caused those heart problems, according to the FDA.

Patients should talk with their health care provider to determine whether Evusheld is an appropriate COVID-19 prevention option for them, the agency advised.

Monoclonal antibodies are laboratory-made proteins that mimic the immune system’s ability to combat harmful pathogens such as viruses. Tixagevimab and cilgavimab target the spike protein of the coronavirus to prevent it from attaching to and entering human cells.

The FDA has given its blessing to three other antibody therapies -- from Regeneron, Eli Lilly and GlaxoSmithKline -- with the U.S. government purchasing hundreds of thousands of doses in advance. All require an IV or injection, and they treat infected people who have the highest risk for severe COVID-19. Two can be used to prevent infection after a possible coronavirus exposure.

But AstraZeneca’s drug would be used differently, as a long-term preventive measure in people who are particularly vulnerable to the virus.

Sources

• U.S. Food and Drug Administration, news release, Dec. 8, 2021

• Associated Press