AstraZeneca’s antibody combination retains neutralising activity against Omicron: Study

AstraZeneca’s Evusheld (tixagevimab co-packaged with cilgavimab), a long-acting antibody combination used in the prevention of Covid-19, has been found to have retained neutralising activity against the Omicron SARS-CoV-2 variant (B.1.1.529), according to a new pre-clinical data.

In this study, Evusheld’s Inhibitory Concentration 50 (IC50), a measure of neutralising potency of an antibody, was measured at 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.

Evusheld’s IC50 for the original strain of SARS-CoV-2, previously referred to as the Wuhan strain, was approximately 1.3 ng/ml and 1.5 ng/ml, respectively.

The early data, generated by pseudovirus testing of the full Omicron variant spike against the combination of tixagevimab with cilgavimab, add to the growing body of preclinical evidence demonstrating that Evusheld retains activity against all tested variants of concern to date, an official statement issued on Friday said.

The study was performed independently by investigators at the US Food and Drug Administration (FDA), Center for Biologics Evaluation and Research. The work was supported by US government research funds.

Mene Pangalos, Executive Vice President, BioPharmaceuticals R&D, AstraZeneca, said: “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.”

Pangalos added: “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. We are working with regulators on applications for the use of Evusheld in treating Covid-19.”

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

Evusheld received Emergency-Use Authorisation (EUA) in the US in December 2021 for pre-exposure prophylaxis (prevention) of Covid-19 in people with moderate to severely compromised immunity due to a medical condition or immunosuppressive medications and who may not mount an adequate immune response to vaccination besides those individuals for whom vaccination is not recommended. The first doses of the drug are expected to become available within days.

About 2 per cent of the global population is considered at increased risk of an inadequate response to a Covid-19 vaccine. Emerging evidence indicates that protecting vulnerable populations from getting Covid-19 could help prevent viral evolution, which is an important factor in the emergence of variants.

Additionally, the TACKLE Phase III outpatient treatment trial of Evusheld showed that it reduced the risk of developing severe Covid-19 or death (from any cause) by 50 per cent compared to placebo in non-hospitalised patients with mild to moderate infection who had been symptomatic for seven days or less.

Leave a Reply

Your email address will not be published.

Back to top button