China's coronavirus has so far killed more than 360 and infected more than 17,000 people around the world, sending stocks lower as markets react to the continued spread of the virus. A single patient treated with remdesivir in Washington state is reported to have made a recovery from the coronavirus.
The drug has to be given intravenously, is experimental and not yet approved for any use, and has not been studied in patients with any coronavirus disease.
The medicine has earlier tested on infected mice and monkeys that suggested Remdesivir can fight coronaviruses.
Gilead's patent application, filed before the virus was identified, cites only the overall family of coronaviruses.
Remdesivir was used to treat the first USA patient with the new virus by doctors at a hospital north of Seattle. His symptoms improved the next day.
Another report published Tuesday by scientists in China added to the enthusiasm, showing that remdesivir blocked the new coronavirus, officially known as 2019-nCoV, from infecting cells grown in the lab. The company said it has provided the drug for emergency use in a small number of patients with the Wuhan virus "in the absence of any approved treatment options".
The trial will include 453 critical patients and 308 less severe patients. A total of 761 patients are participating in the trial.
While the drug is challenging to produce, Gilead is working as fast as possible to produce more, Dr Parsey said.
"There are now limited available clinical supplies of remdesivir, but we are working to increase our available supply as rapidly as possible", McKeel said.
The drug has also been tested on Ebola patients, Xinhua reported. "We are doing this before knowing whether the drug is safe and effective to treat 2019-nCoV", the spokesperson said.
The comments came after the Wuhan Institute of Virology said on Wednesday that it had filed a patent application to use remdesivir to treat the novel coronavirus on January 21, which has sparked debate on China's social media about intellectual property issues.
Gilead, headquartered in Foster City, California, says it applied for a worldwide patient in 2016, including in China, for use of remdesivir against coronaviruses and is awaiting a decision. But the company's application for coronavirus use is still pending, McKeel said.
"The good thing in having a patent is that it would lead to cross-licensing situations that give China more bargaining chips in negotiating the licensing fee with Gilead", said Wang Yanyu, a senior partner at AllBright Law Offices in Beijing.
Under World Trade Organization rules China has the right to declare an emergency and compel a company to license a patent to protect the public.
Scientists are also testing the drug chloroquine as part of a drug discovery approach, where existing antiviral medicines are tested to see if they are effective against a new infection. Researchers are recommending that it also be studied, along with various antiviral medications, including some of the ones used to treat HIV.