Gilead CEO: We're studying new ways to treat coronavirus with remdesivir outside of the hospital
Gilead Sciences CEO Daniel O'Day told CNBC on Monday that the company is continuing to study new ways to use its coronavirus treatment remdesivir on patients, including potentially outside of the hospital all together.

"We're not finished with remdesivir," O'Day said on "Squawk Box," one day after the biopharmaceutical company announced a $21 billion acquisition of Immunomedics that will enhance Gilead's availability of cancer treatments.

Gilead in May received emergency approval for remdesivir from the Food and Drug Administration, allowing it to be used on people who were severely ill with Covid-19 in the hospital. The antiviral drug, which is administered through an intravenous infusion has been shown to help shorten the recovery time of some hospitalized patients.

Reuters reported last week that some large hospital systems in the U.S. are limiting their use of remdesivir to severely ill people. In late August, the FDA expanded its emergency authorization to allow all hospitalized Covid-19 patients to receive the drug. Remdesivir costs hospitals $3,120 for a typical U.S. patient with commercial insurance while the government cost is $2,340.

O'Day said Monday that Gilead this month began trials to look at using IV remdesivir in outpatient settings, which may make it possible to "keep people out of the hospital in high-risk cases."

He noted the California-based company also has been testing the drug, which had previously been studied as a potential Ebola treatment, to be used in inhaled form for Covid-19 patients. Those trials began in July.

"If one could do it without an IV, right to the site of where you get this replication of the virus in the lungs, we're also hopeful that you might be able to treat outside the hospital and prevent patients from ever going to the hospital," said O'Day, who became Gilead CEO in March 2019.

As for the regulatory approval of these potential uses, O'Day said giving people remdesivir through an IV in an outpatient setting such as a nursing home is "probably a shorter timeline."

"The inhaled version, remember, we're moving at light speed in the industry. In fact, from when this virus first showed its head in January, in three months time, we had the first of our gold standard trials," he said. "With a new formulation of a medicine, it does take a little bit longer. So we're in the early stages of testing for [inhaled use]."

Gilead will try to accelerate emergency approvals if possible, he added, but suggested it is likely a 2021 event for more data being available on the efficacy of remdesivir when taken in inhaled form.

"Depending on the results we see over the coming months, with this early stage testing, we may be moving this into later-stage trials toward the end of this year, early next year," he said. "We'll just have to see. We want to follow the science here. We don't to get ahead of it."

There are no FDA-approved drugs to treat the coronavirus. In addition to searching for treatments to lessen the severity of the illness, companies and governments around the world also are racing to develop a vaccine to prevent Covid-19.

More than 29 million people have been infected by the coronavirus worldwide and at least 924,814 people have died, according to data compiled by Johns Hopkins University. The U.S. has more than 6.5 million infections and more than 194,000 fatalities.