Publish date: 24 August 2021

An antibody treatment trialled at UCLH cuts the risk of developing symptomatic COVID-19 by 77%, according to results announced by AstraZeneca who developed the antibody known as AZD7442.

In the multi-country PROVENT trial, which at UCLH was led by Dr Nicky Longley, there were no cases of severe COVID-19 or COVID-19-related deaths in those treated with AZD7442. In the placebo arm, there were three cases of severe COVID-19, which included two deaths.

The treatment was developed with the aim of offering an alternative to a vaccine for people who may not respond to vaccination (for instance where someone has a compromised immune system) or are at increased risk of infection due to factors such as age and existing conditions.

AstraZeneca now plans to apply to health authorities for authorisation of the treatment for potential emergency use.

Dr Longley, an infectious diseases consultant at UCLH, said: “I’m very proud to have been part of this study across sites and across countries, and am encouraged that we are now a step closer to being able to offer protection to those who may not be able to receive a vaccine. It is vital we can offer an alternative to vaccination which is just as protective.”

Antibodies are protein molecules that the body produces to help fight infections. The treatment trialled in PROVENT – ASD7442 – is a monoclonal antibody. These are produced in a laboratory and designed to be injected directly into the body. They differ from vaccines which ‘train’ the immune system itself to produce antibodies.

UCLH is part of two trials looking at use of the antibody treatment. The other trial alongside PROVENT, called STORM CHASER and led by UCLH virologist Dr Catherine Houlihan, looked at use of the treatment in people who had been recently exposed to the SARS-CoV-2 virus.

Results from STORM CHASER showed that for participants known to be virus-free (based on a PCR test) when given the treatment, it significantly reduced the risk of developing symptomatic COVID-19.

Both trials took place at the Vaccine Research Centre at UCLH, which opened in December 2020 to help accelerate the development of new Covid-19 vaccines and treatments.