Positive high-level results from the Tackle Phase III Covid-19 treatment trial showed AstraZeneca's AZD7442, a long-acting antibody (LAAB) combination, achieved a statistically significant reduction in severe Covid-19 or death compared to placebo in non-hospitalised patients with mild-to-moderate symptomatic Covid-19

A total of 90% of participants enrolled were from populations at high risk of progression to severe Covid-19, including those with co-morbidities.

The trial met the primary endpoint, with a dose of 600mg of AZD7442 given by intramuscular (IM) injection reducing the risk of developing severe Covid-19 or death (from any cause) by 50% compared to placebo in outpatients who had been symptomatic for seven days or less. The trial recorded 18 events in the AZD7442 arm (18/407) and 37 in the placebo arm (37/415). The LAAB was generally well-tolerated in the trial.

In a prespecified analysis of participants who received treatment within five days of symptom onset, AZD7442 reduced the risk of developing severe Covid-19 or death (from any cause) by 67% compared to placebo, with nine events in the AZD7442 arm (9/253) and 27 in the placebo arm (27/251).

AZD7442 is the first LAAB with Phase III data to demonstrate benefit in both prophylaxis and treatment of Covid-19 and is easily administered by IM injection.

Mene Pangalos, Executive Vice President, BioPharmaceuticals R&D, AstraZeneca, said: “These important results for AZD7442, our long-acting antibody combination, add to the growing body of evidence for use of this therapy in both prevention and treatment of Covid-19. Early intervention with our antibody can give a significant reduction in progression to severe disease, with continued protection for more than six months.”

Tackle included 903 participants in a 1:1 randomisation AZD7442 to placebo. The primary analysis was based on 822 participants.