Sanofi has started a Phase II/III clinical trial of rheumatoid arthritis drug Kevzara (sarilumab) to treat patients hospitalised with severe Covid-19 infection outside of the US.

The first participant in the study, which is being conducted in Italy, Spain, Germany, France, Canada and Russia, has already been treated.

Sanofi’s partner, Regeneron Pharmaceuticals, is responsible for performing the study’s counterpart in the US, which commenced earlier this month.

Kevzara is a fully-human monoclonal antibody designed to inhibit the interleukin-6 (IL-6) pathway. IL-6 is linked to the overactive inflammatory response in the lungs of severely or critically ill Covid-19 patients.

Sanofi Research and Development global head John Reed said: “Sanofi and Regeneron are relentlessly working to rapidly initiate trials around the world that will help determine whether Kevzara has the potential to play a role in addressing the Covid-19 global health crisis.

“These trials will provide important data to determine whether Kevzara ameliorates the life-threatening complications of Covid-19 infections by counteracting the overactive inflammatory responses in the lungs when damaged by the virus.”

The new multi-centre, double-blind, two-part trial will compare the safety and efficacy of a single intravenous dose of Kevzara to placebo.

Around 300 adult patients hospitalised with severe or critical Covid-19 will be enrolled.

The Phase II part of the study will randomise participants to recieve Kevzara’s higher dose, lower dose and placebo arms.

Based on the Phase II data, the drug will be progressed into Phase III to validate the endpoints, patient numbers and doses.

Following administration of the study dose, patients will be monitored for 60 days, or until hospital discharge or death.