Regeneron (REGN 0.63%) and Sanofi (SNY 2.28%) have started a clinical trial to see if Kevzara -- a drug that has been approved by the Food and Drug Administration as an arthritis treatment -- works on COVID-19. The companies hope that the monoclonal antibody will reduce fever and the need for supplemental oxygen in patients with severe cases of the illness. 

Because they are working with a drug that has already been approved, the companies can skip the phase 1 trial stage, in which a drug's safety profile is established. Kevzara already has a proven safety record in patients. The only question is whether it helps against COVID-19. 

Doctors in Hazmat suits treat sick patient

Image source: Getty Images

Right now, there are no approved drugs for COVID-19. In China, medical authorities have been trying drugs approved for other indications to treat patients with the disease. One is Actemra, an arthritis drug from Roche (RHHBY 0.52%). Actemra and Kevzara are highly similar pharmaceuticals -- interleukin 6 (IL-6) inhibitors approved as treatments for rheumatoid arthritis. 

The reason that researchers view IL-6 inhibitors as a promising avenue here is that the most severe cases of COVID-19 feature a dangerous and excessive immune reaction called a cytokine storm. Chinese health authorities have listed an elevated IL-6 condition as a sign of the disease getting worse. As inhibitors of IL-6, both Actemra and Kevzara might work to ease those patients' symptoms. 

In one small trial in China, medical authorities found that an IL-6 inhibitor rapidly reduced the fevers of COVID-19 patients. And 75% of patients had a reduced need for supplemental oxygen after taking the drug. 

Kevzara will be tested in approximately 400 patients at 16 sites around the country, starting in New York.