(Reuters) – Eli Lilly and Co on Monday said it was launching a study of its rheumatoid arthritis drug baricitinib in patients hospitalized for COVID-19.

The trial is one of several efforts by the U.S. drugmaker to help combat the coronavirus pandemic, which has killed more than 400,000 people globally, according to a Reuters tally.

The drug is being tested to see if it can reduce deaths from the COVID-19 illness and lessen its severity. Scientists at Lilly believe that baricitinib could help suppress a potentially lethal immune response to COVID-19 called “cytokine storm” and reduce COVID-19’s ability to reproduce in infected cells.

The trial began dosing patients last week and plans to enroll around 400 patients globally. Lilly could potentially obtain U.S. regulatory approval for the drug as soon as August, Patrik Jonsson, the president of Lilly Bio-Medicines, told Reuters in an interview.

Lilly has also been working with the National Institutes of Health to study baricitinib, which is branded Olumiant, in a pairing with Gilead Sciences Inc’s antiviral drug remdesivir. That study began enrolling patients last month.

The U.S. Food and Drug Administration granted Gilead’s remdesivir emergency use authorization (EUA) last month, citing results from a U.S. government study that showed the drug reduced hospitalization stays by 31%, or about four days, compared to a placebo.

Lilly could potentially receive approval to use baricitinib in combination with remdesivir by as early as July, Jonsson said.

Seperately, Lilly could have an drug specifically designed to treat COVID-19 authorized for use as early as September if all goes well with either of two antibody therapies it is testing, its chief scientist told Reuters last week.