EUA of AstraZeneca's Pre-Exposure Therapy Offers Hope for Immunocompromised

aAstraZeneca_Nathan Stirk/Getty Images

Nathan Stirk/Getty Images

The U.S. Food and Drug Administration (FDA) has approved emergency use authorization (EUA) for AstraZeneca's Evusheld cocktail as prophylaxis against COVID-19 infection in adults and adolescents aged at least 12 years.

Evusheld, a combination of tixagevimab and cilgavimab, is a long-acting antibody derived from B-cells donated by convalescent patients after contracting the SARS-CoV-2 virus. It was discovered by scientists from the Vanderbilt University Medical Center and then licensed to AstraZeneca in June 2020. 

The combination, formerly named AZD7442, works by binding to specific sites on the virus' spike protein and was observed to provide at least six months of protection from infection after a single dose, as demonstrated by data from the Phase III PROVENT trial. 

In the PROVENT study, Evusheld demonstrated an 83% efficacy compared to a placebo six months after dosage. Another Phase III trial, TACKLE, confirmed its effectiveness when it was applied as outpatient treatment. At present, the drug is being evaluated via the ACTIV-3 study under the National Institute of Health to determine whether it can be used as treatment during hospitalization. 

The EUA is granted for Evusheld's use in adults and adolescents who are moderate to severely immune-compromised due to the use of immunosuppressant drugs or a medical condition that reduces their immune response even after receiving a complete COVID-19 vaccine course. 

It is administered as an intramuscular dose of 150 mg cilgavimab and 150 mg tixagevimab in two consecutive injections. It is not intended for those who are not qualified to receive a vaccine and those who have been recently exposed to someone with SARS-CoV-2 or are currently infected with the virus. 

"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. Evusheld neutralizes all previous SARs-CoV-2 variants to date, and we are working quickly to establish its efficacy against the new Omicron variant," commented Mene Pangalos, executive vice president for biopharmaceuticals R&D at AstraZeneca, in a statement. 

The EUA was also welcomed by industry experts who say that Evusheld is a ray of hope for those who can't be vaccinated. 

"One of the primary questions I keep getting asked by patients is 'When can I hug my grandchildren again?' As a physician and person with a weakened immune system, l am filled with hope now that Evusheld will soon be available to those who can't count on vaccination alone to provide the protection they need," said Dr. Brian Koffman, a retired physician who was part of the PROVENT Phase III trial assessing the drug for prophylactic use. Dr. Koffman is a person living with chronic lymphocytic leukemia (CLL) and is the founder of the CLL Society. 

Evusheld is being developed with funding from the U.S. government. AstraZeneca has already agreed to supply the U.S. with 700,000 doses, rolling out to different states and territories soon. Evusheld has a proven ability to neutralize a number of SARS-CoV-2 variants, including Mu and Delta, and the company is conducting further studies to determine its reaction with the new Omicron variant.

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