Evusheld, was authorised in December 2021 to prevent Covid infection in high-risk people, but has been rendered less effective by the virus’ mutations.
As per AstraZeneca's statement, “Based on in vitro pseudovirus assay laboratory data, Evusheld does not neutralise Omicron subvariants BQ.1, BQ.1.1, BF.7, BF.11, BA.5.2.6, BA.4.6, BA.2.75.2, XBB and XBB.1.5."
Earlier on 20 January, data from the Centers for Disease Control and Prevention (CDC) showed that the fast-spreading Omicron XBB.1.5 is estimated to make up nearly half of US COVID-19 cases, putting it on track to become the dominant subvariant in the country.
In the week ended 21 January, it was estimated to account for 49.1 percent of Covid cases in the country which was a jump from 37.2 percent from a week prior.
As per US FDA's statement, at this point, fewer than 10 percent of the variants currently circulating in the US appear to be responsive to Astra’s treatment.
In the meantime, Astra said in a statement that it’s testing a next-generation long-acting antibody to prevent Covid in immune-compromised people, and aims to make the drug available in the second half of 2023, pending regulatory approval.
In early lab studies, the next-gen antibody was effective against all Covid variants tested, the company said, including those that have thwarted other drugs.
Also Read: COVID new variant: When to get tested amid fears of XBB.1.5 and Omicron BF.7?
“About 2% of the global population is considered at increased risk of an inadequate response to Covid-19 vaccination and could benefit from monoclonal antibodies for Covid-19 protection," the company said.
“AstraZeneca will continue to work with the FDA and other health authorities to collect, assess and share relevant data regarding Evusheld and SARS-CoV-2 variants. Evusheld currently remains authorised in other countries where it is approved for COVID-19 pre-exposure prophylaxis and treatment, including the EU and Japan," the company wrote in a press release.
Also Read: FDA advisers set to consider one-and-done annual covid booster plan
Earlier this month, the agency warned Evusheld was unlikely to work against the rapidly spreading XBB.1.5 variant, which has grown to account for almost half of the country’s Covid cases, but the drug remained on the market until now.
This hasn’t just been a problem for Astra’s antibody. A US National Institutes of Health panel had recommended against using any monoclonal antibodies to treat or prevent Covid in high-risk people because of the drugs’ waning effectiveness.
Evusheld was the last antibody left on the market after the FDA revoked other drugs’ authorizations due to variants. Covid antibody drugs made by Eli Lilly & Co., Regeneron Pharmaceuticals Inc. and a partnership between GSK Plc and Vir Biotechnology Inc. have all been pulled from the market as well.
(With inputs from Bloomberg and Reuters)
