Antibody Combo Gets EUA to Prevent COVID in Vulnerable Groups

The FDA authorized a long-acting monoclonal antibody combination, tixagevimab-cilgavimab (Evusheld), to prevent COVID-19 in immunocompromised individuals and those with a history of a severe vaccine reaction, the agency said on Wednesday.

In its emergency use authorization (EUA), the agency specified that the co-packaged product be used as pre-exposure prophylaxis for individuals ages 12 and up who are not currently infected, have not been exposed to SARS-CoV-2, and who are either moderately or severely immunocompromised or have a history of a severe adverse reaction to a COVID-19 vaccine that rules out completion of the recommended vaccine schedule.

The tixagevimab-cilgavimab combination treatment is administered as two consecutive intramuscular injections, one of each antibody, in immediate succession and may prevent COVID for up to 6 months, the agency said.

“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,” said Patrizia Cavazzoni, MD, director of the FDA’s Center for Drug Evaluation and Research, in a statement.

The phase III PROVENT trial provided the basis for the EUA, with manufacturer AstraZeneca releasing top-line results of the trial in August. These results showed the cocktail significantly reduced the risk of developing COVID-19 symptoms by 77% (95% CI 46-90%) versus placebo in unvaccinated adults ages 59 and up, or adults with a certain chronic medical condition or who were at increased risk of COVID-19 infection. Overall, 3,441 participants received the antibody combination, while 1,731 received placebo.

Additional safety and efficacy data was revealed at IDWeek in October, with researchers pointing out the consistency of the effects across subgroups.

FDA said that adverse reactions included hypersensitivity reactions (including anaphylaxis), bleeding at the injection site, headache, fatigue, and cough. While serious cardiac events were infrequent, more participants in the intervention group had them than in the placebo group.

“It is not clear if Evusheld caused these cardiac adverse events,” the agency wrote.

The FDA emphasized that this antibody cocktail is not meant to be a substitute for vaccination. “The FDA urges the public to get vaccinated if eligible,” the agency stated.