WASHINGTON – A U.S. biomedical firm has announced it will begin additional clinical trials of remdesivir, so far the most promising potential drug for coronavirus, with clinical trials involving about 1,000 patients starting in March.

In a sign that the drug, invented by California-based Gilead Sciences, is gaining traction, a trial involving about 400 patients “with severe clinical manifestations of COVID-19” will skip the placebo step and instead enroll all of them in remdesivir treatment, with either five or 10 days on the drug.

Meanwhile roughly 600 patients “with moderate clinical manifestations of disease,” according to a Gilead statement, will be divided into three groups, with one-third receiving five days of remdesivir treatment, one-third receiving 10 days of treatment, and the remainder receiving “standard care alone,” which could include medicine for pain and fever, fluids, and oxygen, if needed.

In February, Gilead, working with Chinese authorities and medical scientists, initiated two clinical trials in Wuhan, where the outbreak was first reported, and a third “multicenter,” long-term trial, led by the University of Nebraska and “conducted in up to 50 sites globally.”

This fourth round of clinical trials will take place “at medical centers primarily across Asian countries,” the company said, “as well as other countries globally with high numbers of diagnosed cases.”

One goal of the new trial, a senior Gilead official told U.S. reporters, is to find out whether a shorter course of treatment will work. If so, “that automatically doubles the drug supply” while allowing hospitals to treat more patients.

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases at the U.S. National Institutes of Health, mentioned remdesivir Thursday at a White House press conference with U.S. President Donald Trump and Vice President Mike Pence.

Fauci said remdesivir has shown “anti-viral activity in vitro and in animal model.” He also said the trials underway would yield results “reasonably soon whether it works.

“And if it does, we will then have an effective therapy to distribute,” he said.

On Saturday, as the first fatality caused by COVID-19 was reported in the United States, Dr. Jeff Shuren of the U.S. Food and Drug Administration said the agency is “dedicating all available resources to expediting the review of medical products, including diagnostics, to prevent the spread of this outbreak.”

Although the latest trials were announced after Gilead had gone through the process of rapid review and acceptance of remdesivir being filed as an investigational new drug for the treatment of COVID-19, the company points out that “remdesivir is not yet licensed or approved anywhere globally” and that Gilead is providing the drug to “qualified patients with COVID-19 on a compassionate use basis for emergency treatment outside of ongoing clinical trials.”