British–Swedish multinational pharmaceutical firm AstraZeneca has announced that the first participants have been dosed in a Phase I trial of AZD7442, a combination of two monoclonal antibodies (mAbs) in development for the prevention and treatment of COVID-19.

The trial, called NCT04507256, will evaluate the safety, tolerability and pharmacokinetics of AZD7442. The trial will include up to 48 healthy participants in the UK aged 18 to 55 years and is funded by the Defense Advanced Research Projects Agency (DARPA), part of the US Department of Defense, and the Biomedical Advanced Research and Development Authority (BARDA), part of the Office of the Assistant Secretary for Preparedness and Response at the US Department of Health and Human Services.

Should AZD7442 prove to be tolerated and have a favourable safety profile in the trial, AstraZeneca will progress it into larger late-stage Phase II and Phase III trials to evaluate its efficacy as a potential preventative and treatment approach against COVID-19.

Synthesised in the laboratory, mAbs aim to mimic natural antibodies. The treatment has the potential to be given as a preventative option for people exposed to the virus, and to treat and prevent disease progression in patients already infected by the virus.

AZD7442 is a combination of two mAbs derived from convalescent patients with SARS-CoV-2 infection. Discovered by Vanderbilt University Medical Center and licensed to AstraZeneca in June 2020, the mAbs were optimised by AstraZeneca with half-life extension and reduced Fc receptor binding. The half-life extended mAbs should afford at least six months of protection from COVID-19.