USFDA study shows Evusheld retains neutralising activity against Omicron: AstraZeneca

Drug firm AstraZeneca on Friday said that a preclinical study has concluded that its antibody combination Evusheld for the prevention of coronavirus infection has been found to have retained neutralising activity against the Omicron variant.

The study was done independently by investigators at the US Food and Drug Administration (USFDA), Center for Biologics Evaluation and Research. 

The work was supported by US government research funds.

Evusheld (tixagevimab co-packaged with cilgavimab) is a long-acting antibody combination for the prevention of COVID-19.

In the study, Evusheld's Inhibitory Concentration 50 (IC50), a measure of neutralising potency of an antibody, was 171 ng/ml and 277 ng/ml in two confirmatory tests, which is within the range of neutralising titres found in someone who has been previously infected with COVID-19.

"This study shows Evusheld retains neutralisation activity against the Omicron variant. By combining two potent antibodies with different and complementary activities against the virus, Evusheld was designed to evade potential resistance with the emergence of new SARS-CoV-2 variants," Mene Pangalos, Executive Vice President, BioPharmaceuticals R&D, AstraZeneca, said in a statement.

Evusheld is the first long-acting antibody to receive emergency use authorisation in the US for pre-exposure prophylaxis of COVID-19, in addition to authorisations in other countries, and the drug firm is now working with regulators on applications for the use of Evusheld in treating COVID-19, he added.

The Omicron variant was not in circulation during the Evusheld clinical trials.

The company is continuing to collect further data to better understand the implications of this observation in clinical practice.

Additional analyses to evaluate Evusheld against the Omicron variant are being conducted by AstraZeneca and third-party laboratories, with data anticipated very soon, the drug maker noted.