Evusheld significantly protected against symptomatic COVID-19 for at least six months in PROVENT Phase III trial in high-risk populations

Detailed results from the PROVENT Phase III pre-exposure prophylaxis (prevention) trial showed that AstraZeneca’s Evusheld (tixagevimab and cilgavimab), formerly AZD7442, reduced the risk of developing symptomatic COVID-19 by 77% in the primary analysis and by 83% in the six month follow-up analysis, compared to placebo.1 There were no cases of severe disease or COVID-19 related deaths in the Evusheld group through the six-month follow-up.1

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 an inadequate immune response to vaccination.1

Additional pharmacokinetic data showed that Evusheld concentrations remained elevated in serum for six months after administration, supporting that a single dose could provide long-term protection against COVID-19 lasting at least six months.1

The data were published online today in the New England Journal of Medicine.

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Myron J. Levin, MD, Professor of Pediatrics and Medicine, University of Colorado School of Medicine, US, and PROVENT principal investigator on the trial, said: “While COVID-19 vaccines have been highly effective at reducing hospitalisation and death, cases continue to surge and many individuals remain at high risk, including immunocompromised individuals and those who cannot be vaccinated. These important data now published in the New England Journal of Medicine provide confidence that one easily administered intramuscular dose of Evusheld could provide vulnerable populations long-lasting protection. In addition, Evusheld has been shown to neutralise BA.2, currently the dominant circulating COVID-19 variant.”

Mene Pangalos, Executive Vice President, BioPharmaceuticals R&D, AstraZeneca, said: “These data add to the growing body of evidence supporting the use of Evusheld to help prevent symptomatic and severe COVID-19, especially for those individuals who can’t respond adequately to vaccination and need additional protection. Evusheld is now available in many countries around the world, and we are progressing filings in pre-exposure prophylaxis as well as mild-to-moderate treatment.”

In the primary efficacy analysis, a single 300 mg intramuscular (IM) dose of Evusheld reduced the risk of developing symptomatic COVID-19 compared to placebo by 77% (95% confidence interval [CI] 46, 90; p<0.001) at a median follow up of 83 days. Symptomatic COVID-19 occurred in 8/3441 (0.2%) and 17/1731 (1.0%) participants in the Evusheld and placebo groups, respectively.1

Compared to the primary analysis, the extended follow-up analysis demonstrated a greater reduction in COVID-19 incidence in the Evusheld group, with an 83% relative risk reduction (95% CI 66, 91) with Evusheld compared to placebo at a median follow up of 196 days. Symptomatic COVID-19 occurred in 11/3441 (0.3%) and 31/1731 (1.8%) participants in the Evusheld and placebo groups, respectively. Efficacy was generally consistent across participant subgroups, where evaluable.1

There were no cases of severe/critical COVID-19, COVID-19-related deaths or hospitalisations in the Evusheld group by the six-month follow-up analysis; there were five cases of severe/critical disease, seven hospitalisations and two COVID-19-related deaths in the placebo group.1

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Evusheld was generally well tolerated in PROVENT, and no safety issues were identified at either the primary or six-month analysis. Adverse events accrued at similar rates in the Evusheld and placebo groups. The most common adverse event was injection-site reaction, occurring in 2.4% of participants in the Evusheld group and 2.1% of participants in the placebo group.1

Approximately 2% of the global population is considered at increased risk of an inadequate response to COVID-19 vaccination and may particularly benefit from pre-exposure prophylaxis with Evusheld.2,3 This population includes people who are immunocompromised, such as those with cancer or transplant patients or anyone taking immunosuppressive medicines. People at increased risk of exposure to the SARS-CoV-2 virus could also benefit from protection with Evusheld.4-8

AstraZeneca previously announced positive high-level results from the TACKLE Phase III trial in the treatment of mild-to-moderate COVID-19. Full results are being presented at the upcoming European Congress of Clinical Microbiology & Infectious Diseases (ECCMID) and have been submitted for publication in a peer-reviewed medical journal.9