AstraZeneca's Evusheld slashes risk of symptomatic COVID-19 up to 83%

AstraZeneca's monoclonal antibody combination tixagevimab-cilgavimab (Evusheld) reduced the risk of symptomatic COVID-19 infection by 83% over placebo at a median follow-up of 6 months, finds a phase 3 randomized clinical trial published yesterday in the New England Journal of Medicine.As part of an ongoing trial, US and European PROVENT Study Group members, which included AstraZeneca representatives, enrolled 5,197 COVID-naïve adults at elevated risk for inadequate immune response to COVID-19 vaccination and/or exposure to SARS-CoV-2 at 87 sites from Nov 21, 2020, to Mar 22, 2021, before the rise of the Delta and Omicron variants.The researchers randomly assigned participants in a 2:1 ratio to receive one intramuscular 300-milligram dose of either Evusheld (3,460) or a saline placebo (1,737) and contacted them weekly about any COVID-19 symptoms for up to 183 days.Infection in 0.2% with Evusheld vs 1.0% with placeboOver 73% of participants were at elevated risk of infection owing to age older than 60, obesity, impaired immunity, or a high risk for vaccine-related adverse events, and 77.5% had congestive heart failure, chronic obstructive pulmonary disease, or chronic kidney or liver disease.Among Evusheld recipients, 1,161 (34%) were vaccinated against COVID-19, as were 853 (49%) in the placebo group.

Average age was 53.5 years, 43.4% were age 60 or older, 46.1% were women, 14.5% were Hispanic, 17.3% were Black, and 73.0% were White.Of all participants, 52.5% were considered at increased risk of SARS-CoV-2 exposure, including healthcare workers, meatpackers, military personnel, students living in dorms, and others living closely together in Belgium, France, Spain, the United Kingdom, and the United States.Symptomatic