This Phase 3 study will assess the safety and efficacy of a single dose of AZD7442(× 2 IM injections) compared to a placebo to prevent COVID-19.

The actual enrollment of this trial is 5,197 adults who were not vaccinated against COVID-19 and at elevated risk because of their age (≥60 years), a comorbidity (eg, obesity, COPD, immune compromise, history of severe/serious adverse reaction to any FDA-licensed vaccine), or their residential or occupational status. Subjects were randomized 2:1 to receive either 150 mg of tixagevimab plus 150 mg of cilgavimab IM or placebo.

Results

On April 20, 2022, The New England Journal published an Original Article discussing the results of this clinical trial. 

A total of 5197 participants underwent randomization and received one dose of AZD7442 or placebo (3460 in the AZD7442 group and 1737 in the placebo group). The primary analysis was conducted after 30% of the participants had become aware of their randomized assignment.

In total, 1221 of 3461 participants (35.3%) in the AZD7442 group and 593 of 1736 participants (34.2%) in the placebo group reported having at least one adverse event, most of which were mild or moderate in severity. Symptomatic Covid-19 occurred in 8 of 3441 participants (0.2%) in the AZD7442 group and in 17 of 1731 participants (1.0%) in the placebo group (relative risk reduction, 76.7%; 95% confidence interval [CI], 46.0 to 90.0; P<0.001); extended follow-up at a median of 6 months showed a relative risk reduction of 82.8% (95% CI, 65.8 to 91.4).

Five cases of severe or critical Covid-19 and two Covid-19–related deaths occurred, all in the placebo group.

Additionally, AstraZeneca presented at IDWeek an abstract of this PROVENT study. The company shared that  AZD7442 reduced the risk of developing symptomatic COVID-19 by 77% compared to placebo.

There were no cases of severe COVID-19 or COVID-19-related deaths in those treated with AZD7442.

In the placebo arm, the company reported three cases of severe COVID-19, including two deaths.

A key selling point for AstraZeneca’s LAAB is that more than 75% of participants had co-morbidities, which include conditions that have been reported to cause a reduced immune response to vaccination.

 In additional analyses, the reduction in risk of developing COVID-19 was maintained for Evusheld recipients through six months.