New data from the AZD7442 COVID-19 Provent prevention and Tackle outpatient treatment Phase III trials both showed robust efficacy from a one-time intramuscular (IM) dose of the long-acting antibody (LAAB) combination.

In an analysis of the ongoing trial evaluating a median six months of participant follow-up, one 300mg IM dose of AZD7442 reduced the risk of developing symptomatic Covid-19 compared to placebo by 83%.

The AZD7442 Provent trial is the first Phase III trial prospectively designed to evaluate a monoclonal antibody for pre-exposure prophylaxis of symptomatic Covid-19, with targeted inclusion of high-risk and immunocompromised participants. More than 75% of Provent participants at baseline had co-morbidities that put them at high risk for severe Covid-19 if they were to become infected, including people who are immunocompromised and may have a reduced immune response to vaccination.

There were no cases of severe Covid-19 or Covid-19-related deaths in those treated with AZD7442 at either the primary or six-month analyses. In the placebo arm, there were two additional cases of severe Covid-19 at the six-month assessment, for a total of five cases of severe Covid-19 and two Covid-related deaths.

An exploratory analysis of the Tackle outpatient treatment trial, in patients with mild-to-moderate Covid-19, showed that one 600mg IM dose of AZD7442 reduced the risk of developing severe Covid-19 or death (from any cause) by 88% compared to placebo in patients who had been symptomatic for three days or less at the time of treatment.

A total of 90% of participants enrolled in TACKLE were from populations at high risk of progression to severe COVID-19 if they became infected, including those with co-morbidities.

In both PROVENT and TACKLE, AZD7442 was generally well tolerated. No new safety issues were identified in the six-month analysis of PROVENT.

Mene Pangalos, Executive Vice President, BioPharmaceuticals R&D, AstraZeneca, said: “AZD7442 is the only long-acting antibody with Phase III data to demonstrate benefit in both pre-exposure prophylaxis and treatment of Covid-19 with one dose. These new data add to the growing body of evidence supporting AZD7442’s potential to make a significant difference in the prevention and treatment of Covid-19. We are progressing regulatory filings around the world and look forward to providing an important new option against SARS-CoV-2 as quickly as possible.”