AstraZeneca has reported detailed data from the Phase III TACKLE clinical trial where its Evusheld demonstrated to offer clinically and statistically significant protection against progression to severe Covid-19 or mortality from any cause versus placebo.

The findings from the outpatient setting also showed that Evusheld treatment in the early stage of Covid-19 could lead to more favourable outcomes.

Previously called AZD7442, Evusheld is a mixture of two long-acting antibodies (LAABs), tixagevimab (AZD8895) and cilgavimab (AZD1061). 

In June 2020, the Vanderbilt University Medical Center-discovered LAABs were licenced to AstraZeneca.

These antibodies are derived from B-cells of people who had prior Covid-19 infection and attach to various sites on the spike protein of the SARS-CoV-2 virus.

The placebo-controlled, randomised, double-blind, multicentre trial analysed the safety and efficacy of a 600mg intramuscular (IM) dose of Evusheld versus placebo for treating mild-to-moderate Covid-19 in the outpatient setting. 

Carried out at 95 sites in the US, Latin America, Europe and Japan, the trial enrolled 903 subjects. 

According to the findings, Evusheld substantially lowered the relative risk of disease progression or mortality from any cause by 50% by day 29, the primary endpoint of the trial.

Evusheld offered an 88% decline in the risk of severe Covid-19 development or mortality from any cause versus placebo in pre-specified analyses of subjects treated with LAAB combination within three days of symptom development. 

The decline in risk was 67% when subjects were given Evusheld within five days of the development of symptoms.

Furthermore, on a secondary endpoint, treatment with Evusheld offered a 72% decline in the risk of respiratory failure.

In the trial, Evusheld was found to be well-tolerated with adverse events (AEs) reported more frequently in the placebo arm versus the Evusheld arm. 

AstraZeneca BioPharmaceuticals R&D executive vice-president Mene Pangalos said: “We are discussing the TACKLE data with regulatory authorities and continue to progress submissions in both treatment and prophylaxis indications to help combat Covid-19 on all fronts.”    

In April this year, the company reported that Evusheld provided substantial protection against symptomatic Covid-19 for at least six months in the Phase III PROVENT trial in high-risk populations.