Long-Acting Antibody Combination Prevents Symptomatic COVID-19

October 3, 2021

By Brian Hoyle

VIRTUAL -- October 2, 2021 -- Primary efficacy analysis of the phase 3 PROVENT has demonstrated the effectiveness of the prophylactic administration of AZD7442, a long-acting antibody combination of tixagevimab and cilgavimab, in significantly lessening the development of symptomatic coronavirus disease 2019 (COVID-19).

The findings were presented at ID Week 2021, the Annual Meeting of the Infectious Diseases Society of America (IDSA).

“A one-time dose of AZD7442 demonstrated statistically significant protection against symptomatic COVID-19 and was well tolerated,” reported Myron J. Levin, MD, University of Colorado School of Medicine, Aurora, Colorado. “AZD7442 is the first long-acting monoclonal antibody combination that represents a potential new option to augment COVID-19 prevention.”

The antibody combo is derived from B-cells donated by convalescent plasma of patients who had been infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The antibodies have been engineered with half-life extension technology to increase the durability of the therapy for 6 to 12 months following a single administration.

The PROVENT trial (NCT04625725) includes unvaccinated adults aged 18 years and older without prior SARS-CoV-2 infection who may benefit from immunoprophylaxis with antibodies due to an increased risk of either inadequate response to vaccination or SARS-CoV-2 exposure. Participants (mean age 53.5 years, 46% female) were randomised to receive placebo or AZD7442 , delivered as 2 sequential intramuscular injections of tixagevimab 150 mg and cilgavimab 150 mg.

“AZD7442 reduced the risk of developing symptomatic COVID 19 by 77% versus placebo [P

Symptomatic COVID-19 developed in 8 of 3,441 (0.2%) participants who received AZD7442 and in 17 of 1,731 (1.0%) participants who received placebo.

Adverse events occurred in 35% of participants in the AZD7442 arm and in 34% of participants in the placebo arm. Injection site reactions occurred in 2.4% and 2.1% of participants, respectively.

There was 1 case of severe/critical COVID-19 and 2 COVID-19-related deaths in the placebo arm.

Most (75%) participants had baseline comorbidities or other conditions that increased their risk of developing severe COVID-19 if they became infected with SARS-CoV-2. Some had a disease that lessened their immune response or were taking immunosuppressive medications.

Funding for this study was provided by AstraZeneca.

ID Week is sponsored by the IDSA, the Society for Healthcare Epidemiology of America (SHEA), the HIV Medicine Association (HIVMA), and the Pediatric Infectious Diseases Society (PIDS).

[Presentation title: PROVENT: Phase 3 Study of Efficacy and Safety of AZD7442 (Tixagevimab/Cilgavimab) for Pre-Exposure Prophylaxis of COVID-19 in Adults. Abstract LB5]