Ebola Drug Could Be Ready For Human Testing Next Year

Apr 11, 2014
Originally published on April 11, 2014 8:13 pm

The Ebola outbreak in West Africa is terrifying because there's no drug to treat this often fatal disease. But the disease is so rare, there's no incentive for big pharmaceutical companies to develop a treatment.

Even so, some small companies, given government incentives, are stepping into that breach. The result: More than half a dozen ideas are being pursued actively.

And these are boon days for drugs that can treat viruses. Think of treatments for AIDS and hepatitis C.

Potential treatments for Ebola pursue many strategies. These include conventional drugs, custom-built antibodies, and vaccines that are designed not simply to prevent the spread of a disease, but to treat it in people who are in the early stages of infection.

Each idea has shown some promise in animals. But nothing has yet passed critical human testing, so there's nothing ready to be tried during the current outbreak.

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, is hopeful about this multipronged approach, but says, "I think it's really too early to make a prediction about what is the more or less promising one among them."

One challenge is that there are several different species and strains of Ebola-like viruses, so there may not be a one-size-fits-all solution.

But one experimental drug could conceivably fit that bill. It's called BCX4430. Travis Warren at the U.S. Army Medical Research Institute for Infectious Diseases lab in Frederick, Md., has been working on this antiviral drug.

"It worked great against both Ebola virus and [the closely related] Marburg virus" when tested in mice, he says. It also protected guinea pigs from these viruses and yellow fever.

So the next set of tests was in a small number of monkeys who had been infected with Marburg virus.

"When we started the drug either 24 hours or 48 hours after the infection, 100 percent of those animals survived," Warren says.

It's notable that this drug is being developed by a small company, called BioCryst Pharmaceuticals.

"It just wouldn't make the cut at a major company," says Dr. William Sheridan, BioCryst's medical director, who once worked at the drug giant Amgen.

Ebola, scary as it is, has only made about 2,500 people sick since it was discovered in 1976, killing about 1,700 of them. So the market for a drug like this is tiny.

Still, Sheridan says his company has good reason to pursue it, beyond his desire to address an important public health issue.

"There is a market, and the market is the U.S. government," he says.

The government has promised to buy a stockpile of drugs that are effective against Ebola, in case someone should try to use it as a biological agent on the battlefield, or in an act of terrorism. Federal agencies also are helping to pay for the research, so the company is pushing forward as quickly as it can.

"We're currently [manufacturing the] drug and will be conducting typical animal safety experiments that you typically do before you put drugs in humans," Sheridan says. "And once that's successfully completed, I anticipate by the middle of next year that we should have completed phase one studies in people."

Phase one tests will tell them whether the drug is relatively safe, but it won't tell them whether it would actually be an effective treatment. Assuming the drug seems safe, it would be ready for testing in a future outbreak of Ebola.

Of course, most potential drugs don't live up to their early promise, and there's no assurance this one will, either.

But Travis Warren at the Army lab says that given all the advances in developing drugs to treat viruses, something will emerge out of this broad quest for an Ebola drug.

"I'm absolutely certain it will happen," Warren says. "It's just a matter of time."

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Transcript

MELISSA BLOCK, HOST:

The Ebola outbreak in West Africa is unnerving because there's no drug to treat this often fatal disease. The disease is so rare, there's no incentive for big pharmaceutical companies to develop a treatment. Even so, some small companies, given government incentives, are stepping into that breach. NPR's Richard Harris reports that more than half a dozen ideas are being actively pursued.

RICHARD HARRIS, BYLINE: Scientists have made big strides in developing drugs that can treat viruses, like the ones that cause AIDS and Hepatitis C. Some of those ideas are now being applied to Ebola. Approaches include custom built antibodies that can thwart a virus. Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases says there are also vaccines that could be used to treat rather than simply prevent Ebola and related diseases.

ANTHONY FAUCI: These are all in what we call preclinical, which means they're at concept development in an animal that have either not yet gone into the human or are just about ready to go into a human.

HARRIS: Which concept has the inside track?

FAUCI: I think it's really too early to make any prediction about what is the more or less promising among them.

HARRIS: One challenge is that there are several varieties of Ebola-like viruses including the Marburg virus. These viruses cause devastating internal bleeding and death. Travis Warren at the U.S. Army Medical Research Institute for Infectious Diseases says research teams have been trying to custom-make drugs for each of those species and strains.

TRAVIS WARREN: But there had not been a drug readily identified that really would exhibit anti-viral activity against a number of these different viruses.

HARRIS: He's involved in a project to do just that. The experimental drug is called, BCX4430. It's a simple drug that attacks an enzyme that's found in viruses like Ebola and Marburg, but not in people. In his super-high security lab in Frederick, Maryland, he first tested it on mice.

WARREN: And it worked great against both Ebola virus and Marburg virus and then we tested it further in guinea pigs.

HARRIS: It worked great there, too, not only against these viruses, but yellow fever as well. So the next set of tests was in a small number of monkeys who had been infected with Marburg virus.

WARREN: When we started the drug either 24 hours or 48 hours after the infection, 100 percent of those animals survived.

HARRIS: It's notable that this drug is being developed by a small company, called BioCryst Pharmaceuticals. Dr. Bill Sheridan, the medical director, says it's no accident that it's in hands of someone you've probably never heard of.

WILLIAM SHERIDAN: Just wouldn't make the cut at a major company.

HARRIS: Ebola, scary as it is, has only stricken a few thousand people since it was discovered in 1976, and has killed about 1,700. So the market for a drug like this is tiny. Still, Sheridan says his company has good reason to pursue it, beyond a desire to address an important public health issue.

SHERIDAN: There is a market, and the market is the U.S. government.

HARRIS: The government has promised to buy a stockpile of drugs that are effective against Ebola, in case someone should try to use it as a biological agent on the battlefield, or in an act of terrorism. And federal agencies also are helping to pay for the research, so the company is pushing forward as quickly as it can.

SHERIDAN: We're currently making drug and will be conducting typical animal safety experiments that you do before putting a drugs into humans. And once that's successfully completed, I anticipate by the middle of next year that we should have completed phase one studies in people.

HARRIS: Those tests will tell them whether the drug is relatively safe, but it won't tell them whether it would actually be an effective treatment. Assuming the drug seems safe, it would be ready for testing in a future outbreak of Ebola.

SHERIDAN: The earliest that could happen would be about the middle of next year.

HARRIS: Of course, most potential drugs don't live up to their early promise and there's no assurance this one will, either. But Travis Warren at the Army lab says given all the advances in developing drugs to treat viruses, something will emerge out of this broad quest for an Ebola drug.

WARREN: I'm absolutely certain it will happen so it's just a matter of time.

HARRIS: And for people in West Africa who live through frightening outbreaks of these diseases, it can't be soon enough. Richard Harris, NPR News. Transcript provided by NPR, Copyright NPR.