CDC director Robert Redfield told lawmakers Tuesday that Gilead's remdesivir is being used to treat some U.S coronavirus patients on 'compassionate' grounds.

Gilead Sciences (GILD) - Get Report shares traded higher Wednesday after the company's experimental coronavirus treatment was reportedly being used in the United States under federal rules that allow the use of unapproved drugs on compassionate grounds.

The Centers for Disease Control director Robert Redfield told lawmakers on a House appropriations panel Tuesday that remdesivir, Gilead's developing coronavirus treatment that was first designed to combat the Ebola virus, was being used on compassionate grounds in Washington state. Federal Food & Drug Administration rules allow patients to use unapproved drugs in life-threatening situations when all other options have been exhausted.

“For people that are very sick, and we have a number that are very sick, there is an experimental drug called remdesivir that’s available right now in compassionate use," Redfield said. "This country has used it."

Gilead shares were marked 3.3% higher in early trading Wednesday, compared to a 4.5% decline for the S&P 500, to change hands at $74.56 each in a move that would extend the stock's one-month gain to around 10%.

Last month, Gilead said that around 1,000 patients suffering from both moderate and severe coronavirus symptoms were given varying doses of remdesivir as part of a Phase 3 study after the World Health Organization said the drug may be the "only one drug right now that we think may have real efficacy" in treating the rapidly-spreading disease.

Gilead said it expects results from those trials as early as next month, and has vowed to increase supplies "as early as possible" in the near term.

In early February, U.S. doctors treating the first domestic case of the disease used the treatment, which has not yet been approved by any medical authority, on compassionate grounds only to see the patient's pneumonia-like symptoms subsequently improve, according to a New England Journal of Medicine report.