AstraZeneca says its antibody drug prevents COVID-19 infection for six months in high-risk patients

Trial results published by manufacturer AstraZeneca show that a one-off dose of Evusheld reduced the risk of developing symptomatic COVID-19 by 83%, compared to placebo.
A syringe is placed on a document with the AstraZeneca logo

A single injection of the long-acting antibody (LAAB) drug Evusheld (AZD7442) significantly reduced the risk of symptomatic COVID-19 infection for six months in immunocompromised patients, the drug’s manufacturer AstraZeneca has said.

Evusheld is a combination of two LAABs: tixagevimab (AZD8895) and cilgavimab (AZD1061), both of which are derived from white blood cells donated by patients who have been previously infected with COVID-19.

In a statement issued on 18 November 2021, AstraZeneca said that results from the PROVENT trial show that a one-off intramuscular dose of 300mg of Evusheld reduced the risk of developing symptomatic COVID-19 by 83%, compared to placebo.

A spokesperson from AstraZeneca told The Pharmaceutical Journal that the trial data have been submitted to the Medicines and Healthcare products Regulatory Agency (MHRA) as part of a rolling review of the drug.

The trial — which was conducted between November 2020 and May 2021 — has yet to be published in a peer-reviewed journal and included 5,197 participants, of whom 3,460 received the drug and 1,737 received a saline placebo.

More than 75% of participants had pre-existing comorbidities, such as diabetes, severe obesity or cardiac disease, and “may have a reduced immune response to vaccination”.

Over a six-month period, there were no cases of severe COVID-19 or COVID-19-related deaths in the intervention group. In the placebo control group, five people developed severe COVID-19 and two people died with the disease within six months.

In a further trial of the same drug, patients who had already developed mild-to-moderate COVID-19 received a single 600mg injection within three days of developing symptoms.

This trial, called TACKLE, included 903 participants, 90% of whom were considered to be at high risk of developing severe COVID-19 following infection. Half of the trial participants received the drug and the others received a saline placebo.

Results from the trial, which have not yet been peer reviewed, suggest that the drug reduced the risk of developing severe COVID-19, or death from any cause, by 88% compared to placebo.

Hugh Montgomery, professor of intensive care medicine at University College London and principal investigator of the Evusheld drug, said: “These compelling results give me confidence that this long-acting antibody combination can provide my vulnerable patients with the long-lasting protection they urgently need to finally return to their everyday lives.”

A spokesperson for the MHRA said: “Approval applications are commercially sensitive. Any that are received will be evaluated in the shortest time possible while maintaining our high standards of safety, quality and effectiveness.”

In September 2021, the NHS began offering monoclonal antibody cocktail Ronapreve (casirivimab and imdevimab; Roche Products Ltd) to adults aged over 50 years and immunocompromised people aged 12–49 years, if they have been hospitalised with COVID-19. This was extended in November 2021 to patients who acquired COVID-19 in hospital.

Last updated
The Pharmaceutical Journal, November 2021;Online:DOI:10.1211/PJ.2021.1.116788