Gilead Sciences Inc. shares climbed in late trading Thursday after a report that a group of patients being treated in Chicago were “seeing rapid recoveries in fever and respiratory symptoms.”

The report, from the medical news publication Stat, cited a video made by a researcher at the University of Chicago who is helping conduct a trial of Gilead’s drug remdesivir. The researcher, infectious disease professor Kathleen Mullane, said that most patients had been discharged from the hospital and only two had died, according to Stat.

Gilead’s drug is one of the most-watched therapies being studied for treatment of COVID-19 patients. It’s conducting two trials of the drug in moderate and severe patients, with the goal of enrolling 4,000 people in the trials. The University of Chicago enrolled 125 patients, most of whom had severe disease, according to Stat.

Shares of the company surged 10% in trading after the market closed.

The Chicago results are a tiny but promising sliver of the overall trial. Almost all patients recover from the disease, which has made it important to conduct tests which compare treatments against a placebo. While the trial in moderate patients contains a placebo group, Gilead’s trial of severe patients does not.

Mullane didn’t immediately respond to a request for comment. Researchers have collected information from the first 400 patients enrolled in the trial and Gilead plans to “lock” the data on Thursday, meaning the results could come soon, Stat said.

More coronavirus coverage from Fortune:

—22 million lost their jobs in the past month—real unemployment rate likely near 18%
—How Fortune 500 companies are utilizing their resources and expertise during the pandemic
—Inside the surreal “Mask Economy”: Price-gouging, bidding wars, and armed guards
—The IRS just launched “Get My Payment” portal for tracking your stimulus check status
—How every sector of the S&P 500 has been impacted by the coronavirus selloff
—If you’ve been a little busy lately, here’s what’s going on with the 2020 election
—Military experts: We need to fight coronavirus like we fight insurgents on the battlefield
—PODCAST: COVID-19 might have upended the concept of the best companies of the year
—VIDEO: 401(k) withdrawal penalties waived for anyone hurt by COVID-19

Subscribe to Outbreak, a daily newsletter roundup of stories on the coronavirus pandemic and its impact on global business. It’s free to get it in your inbox.