Evusheld长效抗体组合保留了对Omicron变体的中和活性

Introduction: AstraZeneca's Evusheld (tixagevimab co-packaged with cilgavimab) retains neutralizing activity against the Omicron SARS-CoV-2 variant (B.1.1.529, Omicron), a long-acting antibody combination for the prevention of COVID-19.

Results from the PROVENT trial of Evusheld, which includes the antibodies tixagevimab and cilgavimab, showed a statistically significant reduction in the risk of developing symptomatic COVID-19 compared with placebo (77% in the initial analysis and 83% in the median 6-month analysis), with protection against the virus lasting at least 6 months.

In studies by the University of Oxford and the University of Washington, Evusheld's inhibitory concentration 50 (IC50), a measure of the neutralizing potency of an antibody, was 273 ng/ml and 147 ng/ml, respectively. These levels are within the range of neutralizing antibody titers in individuals who have been previously infected and naturally recovered from COVID-19.

The data come from laboratory tests using real, live viruses isolated from individuals infected with the Omicron variant, which is considered the "gold standard" for antibody neutralization studies. Evusheld is one of only two authorized antibody therapies to show neutralizing activity against Omicron and all other variants of concern in both studies.

These findings are consistent with pseudovirus neutralization data from an independent investigative study published by the U.S. Food and Drug Administration (FDA) on December 16, 2021, and coupled with growing preclinical evidence confirming that Evusheld retains activity against all SARS-CoV-2 variants of concern tested to date.

During the Evusheld clinical trial, the Omicron variant was not yet prevalent. AstraZeneca will continue to collect additional data to better understand the impact of these data in clinical practice. Data from both studies will be submitted for publication in a peer-reviewed journal.

In December 2021, Evusheld received Emergency Use Authorization (EUA) in the United States for COVID-19 pre-exposure prophylaxis. The applicable population mainly includes groups with moderate to severe immune impairment due to medical conditions or immunosuppressive drugs and the inability to adequately respond to the COVID-19 vaccine, as well as individuals for whom vaccination against COVID-19 is not recommended.

About 2% of the global population is considered to have an inadequate response to COVID-19 vaccines and is therefore at increased risk. Recent evidence has emerged that protecting vulnerable populations from COVID-19 can help prevent the virus from evolving (an important reason for the emergence of mutant strains).

References:

https://www.astrazeneca.com/content/astraz/media-centre/press-releases/2021/evusheld-long-acting-antibody-combination-retains-neutralising-activity-against-omicron-variant-in-studies-from-oxford-and-washington-universities.html