08/11/2014 11:33 EDT | Updated 10/11/2014 05:59 EDT

Tekmira's experimental Ebola drug pushes stock up again

Shares in Burnaby, B.C.-based Tekmira Pharmaceuticals soared for a second day on Monday after U.S. regulators fast-tracked one of the company's experimental drugs for use on humans to treat the Ebola virus.

Shares in Tekmira gained another $4 to trade at $27.52 when the TSX opened on Monday. That's almost twice what the company was worth on Thursday of last week.

That evening, after markets closed, the company revealed that the U.S. Food and Drug Administration had lowered what's known as a "full clinical hold" on the company's experimental drug to a partial hold.

"This action enables the potential use of TKM-Ebola in individuals infected with Ebola virus," the company said in a press release.

That news sent the shares soaring almost 50 per cent on Friday, and the optimism continued on Monday when stock markets reopened.

Earlier preclinical studies suggested that when the company's drug, known as TKM-Ebola, was used in previously infected non-human primates, the result was 100 per cent protection from an otherwise lethal dose of Zaire Ebola virus.

That's the strain of the virus that has killed more than 900 people in central Africa in the past month, the largest recorded death toll since the virus was discovered in 1976.

Tekmira already launched a human clinical trial for the drug in humans in January, news that pushed the company's stock up to an all-time high of $33 in March. But that trial was put on hold in July after some patients in the trial experienced problematic immune responses.

The company is still on hold for the multi-ascending dose portion of the study on healthy patients, but the FDA's move opens the door to single doses for people already infected.