Experimental Drug Used for Ebola-Related Virus Shows Promise,2014

Experimental Drug Used for Ebola-Related Virus Shows Promise
The new york time

An experimental drug has completely protected monkeys from lethal doses of a virus related to Ebola, bolstering confidence that a similar medicine might be effective if deployed in the current outbreak in Africa, researchers reported on Wednesday.

The researchers said that the drug, which is being developed by Tekmira Pharmaceuticals, kept all monkeys alive in a study, even if given as late as three days after exposure to the Marburg virus, when the virus was already detectable in the animals’ blood.

Both Marburg and Ebola are filoviruses that cause deadly hemorrhagic fever characterized by vomiting, diarrhea, uncontrolled bleeding and possible organ failure. Tekmira, which is based in British Columbia, has a separate drug for Ebola that is already in early testing in healthy human volunteers. Both drugs work the same way — turning off viral genes through an approach called RNA interference.

 The Marburg virus, seen through an electron microscope. Credit Thomas W. Geisbert/University of Texas Medical Branch

Some experimental drugs for Marburg and Ebola have been shown in animal studies to be effective when given shortly after infection. But in a real epidemic like the one in West Africa, most people do not know they have been infected until they get sick, which can be several days later. So there is a need for drugs that will treat a disease that is already underway.

Tekmira’s Marburg drug moves in that direction. The virus was detectable in the monkey’s blood three days after exposure, corresponding to the time an infection might first be diagnosed using a test.
The study demonstrates the “real-world utility of this technology,” said Dr. Thomas W. Geisbert, a professor of microbiology and immunology at the University of Texas Medical Branch at Galveston and a senior author of the study, which is being published in Science Translational Medicine. He said more studies were being planned
to determine whether the drug could be used even later.
Dr. Daniel G. Bausch, an associate professor of tropical medicine at Tulane University, who was not involved in the study, said effectiveness at three days postexposure was not that useful. In an outbreak, only people who are closely monitored — such as those who have had contact with an infected person — might get a diagnosis based on a blood test, before symptoms appear.

“The vast majority of people come in after they are sick for a couple of days,” Dr. Bausch said. In the study, even the monkeys that did not get the drug did not show symptoms until about six days after exposure.

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