Bay Area-based Gilead Sciences developed a drug several years ago, remdesivir, to treat coronaviruses which still had not received approvals for use from any federal government, and now a World Health Organization (WHO) official has said that it is "the only drug right now that we think may have real efficacy" against the novel coronavirus that first appeared in China.

Shares in Gilead jumped up over four percent Monday after the comment by the WHO's assistant director-general Bruce Aylward. As KPIX reports, on a day when markets were tumbling worldwide on fears of a pandemic, Gilead Sciences was the top performing stock on the S&P 500, and it was just one of two stocks on the Nasdaq that was trading up.

As SFist reported several weeks ago, Gilead is likely to be in an ongoing trade-related fight with China over the usurping of its patent on remdesivir for treatment of the coronavirus in China. A lab associated with the Chinese government filed its own patent for the drug in January, after the outbreak began, even though Gilead filed for a patent for the drug to treat all coronaviruses generally three years ago, and that never got approved in China.

Clinical trials for remdesivir in humans are ongoing in China, and results could be available within weeks as Aylward explained in a press conference in Beijing today.

Gilead specializes in anti-viral medications, and they've been most well known in recent years for their drug Truvada, which has been used for PrEP (pre-exposure prophylaxis) in gay men and others looking to prevent HIV infection.

Remdesivir was developed as an experimental drug that has been used to treat the Ebola virus, and has been found to be effective against coronaviruses as well. It was already reportedly being used in a cocktail with a second drug to treat novel coronavirus patients in Italy in recent weeks.

Previously: Bay Area-Based Gilead Sees Potential Legal Conflict With China Over Its Coronavirus Drug