This transmission electron microscope image shows SARS-CoV-2 -- also known as 2019-nCoV, the virus that causes COVID-19 -- isolated from a patient in the US. Virus particles are shown emerging from the surface of cells cultured in the lab. The spikes on the outer edge of the virus particles give coronaviruses their name, crown-like. Credit: NIAID-RML

French pharmaceutical giant Sanofi and American drugmaker Regeneron said Monday they have started clinical trials for a new drug in patients hospitalised with severe COVID-19 infections.

In a statement they said phase 2 and 3 trials were under way for Kevzara, an immunosuppressor.

Regeneron will trial in the United States, while Sanofi plans trials initially in Italy, particularly hard hit by the novel coronavirus pandemic.

Kevzara, the for sarilumab, an antibody that blocks the ability of some viruses to latch on to humane immune cells, has been in development since 2017.

Specifically it inhibits the immune receptor that plays a key role in lung inflammation, something severe COVID-19 patients suffer from.

Around 400 patients will take part in the studies, which will evaluated the effect of Kevzara on fever and oxygenation levels of patients.

It will also look at how the drug works over the long term in reducing , and potentially how it can reduce the need for respiratory apparatus in hospital.

The number of novel coronavirus cases globally stood at 168,250 with 6,501 deaths, across 142 countries and territories at 0900 GMT Monday, according to an AFP tally based on official sources.