Shares of Gilead Sciences Inc rose 10% in early trading on Friday after a report that patients with COVID-19 treated with the company's experimental drug, remdesivir, in a clinical trial showed rapid recovery in fever and respiratory symptoms.
US Housing and Urban Development Secretary Ben Carson, a noted surgeon who is a member of the White House coronavirus task force, said on Friday that Gilead Science's remdesivir appeared to be a promising treatment for COVID-19.
"It is very promising and it has been utilized in various places, not just in one clinical study," Carson told Fox Business Network.
There are currently no approved treatments or vaccines for the coronavirus, which has infected 2.14 million globally, according to a Reuters tally, and remdesivir is one of the treatments that has captured investor's attention.
But analysts and the company urged caution on drawing conclusions from the report by medical news website Stat that also helped buoy the broader markets.
Gilead said the totality of the data from the trial needed to be analyzed, and expects to report results from a study in severe COVID-19 patients at the end of the month, and data from other trials in May.
The report said the University of Chicago Medicine Hospital was seeing rapid recoveries in fever and respiratory symptoms in patients with severe COVID-19 in a trial of the drug it was participating.
"While the article paints a pretty picture, we think the ensuing exuberance shows a lack of critical analysis," said Baird analyst Brian Skorney.
Skorney added investors looking for a definitive conclusion when the severe study reads out will likely be disappointed as the study offers no control, "just five days of remdesivir vs. 10 days of remdesivir."
Wall Street rose on Friday, boosted by President Donald Trump's new guidelines to reopen the economy and Boeing's plans to resume production.
"There will no doubt be cautionary announcements by various scientific bodies about the validity of a partial set of results from a tiny trial," said Jeffrey Halley, a markets analyst at OANDA.
"Markets, though, will likely do their very best to ignore those, preferring to concentrate on ... a potential treatment for COVID-19 symptoms."