US experts trial AZ's long-acting COVID-19 antibody combination

An international trial led by US experts is to begin testing AstraZeneca’s long-acting antibody combination therapy to treat COVID-19.

The combination known as AZD7442 is to be added to the phase 3 adaptive trial called ACTIV-3, where investigators add new sub-studies of investigational new agents.

It is sponsored by the US-government funded by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.

In 2020, researchers at Vanderbilt University Medical Center, Nashville, Tennessee, isolated antibodies from two patients who had recovered from COVID-19.

These antibodies, which were licensed to AstraZeneca, formed the basis for the synthetic antibodies included in AZD7442.

AZ went on to engineer the antibodies to have a longer half-life in the body with its proprietary technology.

While the antibody may act as both a treatment and a means of preventing infection, the ACTIV-3 trial will only be testing its efficacy as a therapy for people who are already infected.

The sub-study of AZD7442 will run in parallel with two other antibody studies – one is testing GlaxoSmithKline and Vir Biotechnology’s VIR-7831.

The other is testing a combination of two antibodies dubbed BRII-196 and BRII-198, developed by Brii Biosciences, based in North Carolina and Beijing.

The first patients tested with AZD7442 will be hospitalised patients with mild-to-moderate COVID-19 and fewer than 13 days of symptoms.

They will be randomly selected to receive either a saline placebo control or one of the three experimental therapeutics.

After five days, the participants’ medical condition will be assessed on two seven-point ordinal scales, each ranging from being able to undertake usual activities with minimal or no symptoms to death.

Once around 150 people have been assessed with mild to moderate disease a further 700 people may be added who may have more severe cases.

This will test whether the combination reaches its primary goal, which is to assess how many patients are discharged from hospital and have lived at home for 14 consecutive days.

AZ started its own UK-based STORM CHASER trial of AZD7442 in December and last month added mobile sites, in a bid to catch up with already-approved rivals from Eli Lilly and Regeneron.