Washington (AFP)

The US National Institutes of Health (NIH) announced on Tuesday the start of large-scale clinical trials to test a drug designed specifically to treat Covid-19.

It is an antibody against the coronavirus called LY-CoV555, discovered in the blood of a recovering patient by the Canadian company AbCellera Biologics. This antibody was then developed synthetically in order to be produced in industrial quantities by the American Lilly Research Laboratories.

The phase 3 trial (the last phase) will begin by recruiting 300 volunteers worldwide, hospitalized patients but with mild or moderate symptoms. Half will receive the drug (by injection), the other half a placebo, in order to discover the real effectiveness of the treatment. All will also be treated normally against Covid-19.

Another arm of the clinical trial will test for synthetic antibodies in outpatients.

Antibodies are proteins that the immune system deploys to attach to invading viruses and prevent them from entering cells in the human body.

The vaccines aim to trigger, in patients not infected with the coronavirus, the production by the immune system of these antibodies, in a preventive manner, according to several methods which are being tested around the world.

For people who are already sick, two treatments have been approved so far, remdesivir and dexamethasone.

Another treatment option currently being evaluated is to inject the antibodies taken from people who have been infected but have recovered, which is called convalescent plasma. This option, if it proves effective, is however not possible on a large scale, which explains the development of synthetic antibodies, called monoclonal antibodies.

© 2020 AFP