After data indicated a higher dose may be more successful in preventing infection by Omicron subvariants of SARS-CoV-2, the Food and Drug Admnistration (FDA) last week revised their emergency use authorization for AstraZeneca’s monoclonal antibody Evusheld, which uses blood cells from COVID-19 survivors to protect certain types of patients.
“Evusheld is a combination of two long-acting antibodies—tixagevimab and cilgavimab—derived from B-cells donated by convalescent patients after SARS-CoV-2 virus,” according to AstraZeneca.
The FDA said Evusheld should be administered at twice the dose that was initially recommended for those already covered by the emergency use authorization: patients who may not benefit from COVID-19 vaccines. These include the immunocompromised who “may not mount an adequate immune response to COVID-19 vaccination” and patients advisded against receiving a vaccination “due to a history of severe adverse reaction,” the FDA said.
The FDA said people who have already received Evushield should go back for an additional dose as soon as possible and that new patients receiving the drug should be given the highe dosage.
“The dosing regimen was revised because available data indicate that a higher dose of Evusheld may be more likely to prevent infection by the COVID-19 Omicron subvariants BA.1 and BA.1.1 than the originally authorized Evusheld dose,” FDA explained.
“It’s great that there continues to be good science in understanding the impact of these monoclonal antibodies on the new variants or maybe the impact of the variants on the efficacy of these,” Dr. Dorry Segev, a professor of surgery at Johns Hopkins Medicine, told CNN.
“The tricky part is to get the word out to immunocompromised people that it is important for those who will benefit from this to seek this therapy,” said Dr. Dorry Segev, noting the supply and distribution challenges of getting Evusheld to the patients who need it. The Centers for Disease Control CDC estimates there are about seven million immunocompromised people among U.S. adults.
According to the U.S. Department of Health and Human Services, the government has so far shipped nearly 600,000 courses of Evusheld across the United States and announced in January the purchase of an additional 500,000 doses.