Gilead Sciences (GILD -0.82%) shot up as much as 13% on the news that its failed Ebola drug, remdesivir, showed promising initial signs of helping patients with the coronavirus. In an official statement before the weekend, the company announced it was working together with U.S. and Chinese health regulators to see whether remdesivir could improve patient symptoms.

The company stated that remdesivir saw some success in treating patients with SARS and MERS, two other viruses with similarities with the coronavirus when tested in animals. Remdesivir was also tested on one U.S. coronavirus patient prior to the weekend, who showed an impressive improvement in symptoms following a single dose.

Close up depiction of virus cells in the body.

Image source: Getty Images.

The New England Journal of Medicine reported that a U.S. patient received a dose of remdesivir from doctors on a compassionate use basis. Whereas the patient had been showing signs of pneumonia, fever, and required supplemental oxygen, after remdesivir was given, all symptoms disappeared except for a cough and mucus buildup in the nasal cavity (rhinorrhea).

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While impressive, further clinical tests need to be performed before Gilead's remdesivir can be recommended for widespread coronavirus treatment. Other pharmaceutical giants are also hoping to develop a treatment, with Johnson & Johnson and GlaxoSmithKline working on their own vaccines. AbbVie stated it saw positive results by mixing two HIV medications with another drug called Tamiflu.

However, the biggest winners over the past few weeks have been small-cap specialty vaccine producers. Moderna and Inovio Pharmaceuticals have seen substantial swings in their stock prices as the coronavirus continues to spread. There are now 362 confirmed deaths from the outbreak so far.