Gilead Sciences is expanding clinical trials of its experimental antiviral drug, remdesivir, for the treatment of COVID-19 into several Asian countries outside China, including Taiwan, the US biotechnology company said in a statement.

Starting next month, the drug is to be tested among 1,000 COVID-19 patients at medical centers across Asia, it said.

The studies would assess two dosing durations of remdesivir, administered intravenously.

One of the trials would randomly enroll about 400 patients with severe clinical manifestations of COVID-19 to receive either five or 10 days of remdesivir, while the second trial would involve about 600 patients with moderate clinical manifestations, who would receive five or 10 days of remdesivir or standard care, the statement said.

Taiwan wanted to bring in the antiviral drug by submitting a request for compassionate use, an option that allows the use of an unapproved drug or medical device for treatment outside of clinical trials, National Taiwan University executive vice president Chang Shan-chwen, who also serves in the Central Epidemic Command Center, said on Thursday.

However, the request has not been approved due to strict restrictions on exports of such unauthorized medicine by the US Food and Drug Administration, Chang said.

Only a small quantity of the experimental antiviral drug would be available to patients participating in the clinical trials to evaluate its safety and efficacy, he said, adding that Taiwan has obtained Gilead Sciences’ approval to start local trials along with several other Asian countries.

The US drugmaker is to sign a contract with three hospitals — one each in northern, central and southern Taiwan — to conduct the trials, Chang said.

Taiwan’s hospitals are gearing up for the clinical trials, which are expected to start in the middle of next month at the earliest, he said.

Remdesivir is the only therapy that has shown promise for treating COVID-19.