Experimental Ebola drug saves monkeys, but this will mean for humans?

21:03
Experimental Ebola drug saves monkeys, but this will mean for humans? -

SAN DIEGO, California- Last Wednesday, during a discussion entitled "Stop the deadly Ebola Outbreak" held at the Scripps Research Institute here a journalist from the local TV repeatedly pushed one of the panelists star Kevin Whaley, CEO of San Diego biopharmaceutical Mapp.

After Whaley said he did not know if zmapp now famous experimental antibody cocktail of his business used to treat victims of Ebola, really worked, the reporter went to the press. "from what you've seen in your search and your heart is said you say? "

the audience of 100 or more people broke into nervous laughter.

" I am not prepared to speculate on that, "said Whaley.

the tenacious journalist, he gave another essay, referring to two American health workers who were infected with Ebola in Liberia, returned to the United States and zmapp received, and lived to talk about it. "What joy was to see the two missionaries walk to the hospital?"

"It was certainly very satisfying, and hopefully zmapp played some role in this," said Whaley. "But it remains to be seen."

The exchange sets light the hope of increasing biomedical some action such as treatment-as zmapp allow more people to survive Ebola infections. time and again, however, the hope and hype became knotted together.

Today node is sure to grow tighter with online Nature encouragingly monkey experiment with zmapp, in which 100% of infected monkeys survived. It is sure to further enhance expectations of a cure and further confuse the public about how nearly one remedy might be. Even the authors of the new warning from the study that the extension of monkey results the man could be a long and difficult task.

the experiments conducted by Gary Kobinger of Canada Agency of public health in Winnipeg, first tested combinations of Ebola antibody made by his laboratory Bio Mapp and to find a cocktail that works best in guinea pigs and monkeys. They chose the concoction now called zmapp and gave three groups of six monkeys; all received an intramuscular injection of high doses of Ebola virus. A group of three control monkeys were given dummy medicines.

The treated monkeys each received a total of three doses of zmapp, one every 3 days. Treatment started 3 days post-infection for a group, to 4 days for another, and 5 for a third. All 18 monkeys had evidence of infection, many fell ill and almost died two.

In the end, 100% of the treated monkeys survived, and 100% of control animals died quickly. Although the experiment used an old Ebola virus which is different from the strain currently in West Africa, the researchers showed in a test tube study zmapp also worked against the most recently isolated viruses.

The results are "a monumental achievement," wrote virologist Thomas Geisbert, who studies Ebola at the University of Texas Medical Branch in Galveston, in an editorial Nature accompanying 'study.

"It is a great study," said Geisbert science Insider. "I have shelves and shelves and shelves of things that inhibit Ebola virus in cell culture and a small percent inhibition in guinea pigs or mice. And I have shelves and shelves of things that work in guinea pigs and mice but not in monkeys. If you save 100% of the monkeys up to 5 days after infection, it's a huge bar to clear. "

in a teleconference held by Nature today Kobinger said it was "quite remarkable" that they could save the infected animals which had advanced disease, which he called "a very important step in the fight against Ebola. virus "But Kobinger also pointed out that many unknowns remain about the differences between this monkey model and human infection.

to start, most humans are infected through exposure to bodily fluids of people with Ebola and not by needles which hold a huge bowl of virus injected into their muscles. This kills the monkeys on average in 8 days, then it usually takes 3 to 21 days for humans to develop symptoms. "It is very difficult to translate" the progression of the disease in the monkey model to humans, Kobinger said. But a monkey infected by this route and are not treated for 5 days is 3 days away from death, he said, indicating that zmapp worked well in the disease.

The monkeys were given three doses of zmapp, and he may need a second before the level of the Ebola virus in their blood dropped-viral load. With the seven treated humans, a person who died received a single dose, and no one has yet reported how many doses the others received. Kobinger said he "would not expect" a single dose of work. "What the antibody is really doing is to gain time," said Kobinger, stressing the importance of proper medical treatment on survival.

Kobinger said he did not know whether the antibodies had an effect on viral load in these patients because they were experimental zmapp on a "compassionate use". "When each of clinicians or clinical teams that have been using zmapp release their data, we will have a better idea of ​​perhaps efficiency, but even then it is difficult because it is not really designed study" Kobinger said. "Unfortunately, it may be limited what we will really learn these seven patients."

In preliminary experiments not reported in Nature Korbinger said he in vivo evidence that zmapp works against the strain currently circulating in West Africa. He said future experiments will analyze the impact of providing monkeys infected with effective intensive care. His group also wants to see how low of a dose of zmapp they can give infected monkeys and save them. "One thing that is very urgent for us to do is a dose-escalation study so that we can see that the minimum amount of antibody is then maybe with the same amount of material that we could do more", they say he.

Availability zmapp is crucial for the growing number of people who want access to it on a compassionate basis. Mapp Bio said it now has more zmapp at hand. Kentucky BioProcessing in Owensboro pushes zmapp antibodies in tobacco plants. In a press release in 2012, Chief Operating Officer of the company, Barry Bratcher, said he had a fully automated production system "that works in accordance with good manufacturing practice" and could "generate a new batch of antibodies in two weeks to respond quickly to new threats and new homes. "Bratcher did not respond to an e-mail from science Insider to discuss this prediction.

On the panel talk Scripps, Whaley said science insider they were still trying to solve the problems of production. "It is clear that we have material misstatement [the production time needed]," said Whaley. "This was clearly not our intention."

Questions have also been raised about how it was decided to give zmapp the seven people who received zmapp far, two of which were from Europe and two states. Whaley said the company responds to requests that come through the US Food and Drug Administration and has no say in who ultimately received the product.

Two of the seven patients died zmapp. Their results ultimately say nothing about the treatment: The people received the drug at different stages of the disease, and four were evacuated to rich countries for top-notch care probably the most important factor for survival . No information was released about the effect of the antibodies had their virus levels. Moreover, it is an experience without control. "These people do not have an identical twin who was infected on the same day and not to treat," said Scripps structural biologist Erica Ollmann Saphire, who was a panelist at the event, he helped Mapp and Bio select antibodies. "That's why we need to make the human clinical trial."

Human studies of zmapp should begin in early 2015.

Meanwhile, the Ebola cases continue to rise. The World Health Organization as of yesterday reported 3069 cases and 1552 deaths, a fatality rate of 52%. Senegal today announced its first case

* Ebola files :. Given the current Ebola outbreak unprecedented in terms of the number of people killed and the rapid geographic spread, Science and Science Translational Medicine made a collection of research articles and news on the viral disease available for researchers and the general public.

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