5 things to know about the experimental Ebola drug

WATCH: A plane carrying the second American aid worker infected with Ebola is now on U.S. Soil. The patient’s arrival comes as another person in New York is being tested for the deadly disease. Omar Villafranca has the story.

TORONTO — As the Ebola crisis unfolded last week, the story of two American aid workers who tested positive with the disease gained worldwide attention. This weekend, both missionary workers were given an experimental drug that allegedly saved their lives.

Officials were tight-lipped about the drug in question but by Monday, U.S. reports poured in pointing to a therapy called ZMapp.

Here’s what you need to know about the experimental drug:

It has Canadian fingerprints all over it

While the unlicensed treatment is made by California company Mapp Biopharmaceutical, it was produced with the help of Canadian research. Parts of the antibodies in the therapy are the product of years of research done at the Public Health Agency of Canada’s National Microbiology Laboratory (NML) in Winnipeg.

“Canada is a world leader in research and we are proud of the advances made at the NML in this area,” a PHAC spokesperson told The Canadian Press via email.

READ MORE: Canadian research at core of experimental Ebola drug

Mapp Pharmaceutical president, Larry Zeitlin, told Global News that ZMapp is a collaboration between Mapp and Toronto-based Defyrus Inc. The U.S. government and the Public Health Agency of Canada were also involved, the company said.

Dr. Frank Plummer, who was head of the Winnipeg lab, said he was delighted to hear that the Canadian work helped pave the way for the ZMapp therapy.

“This is really gratifying to see the work come to fruition,” he told the wire service.

It’s a drug cocktail

ZMapp is made up of three monoclonal antibodies, which are disease-fighting proteins that can target a specific part of an invading pathogen.

While reports refer to the treatment as a serum, Zeitlin clarified to Global:

“Serum is a product derived from blood – human or animal. Monoclonal antibodies are protein drugs that are manufactured.”

The three portions of the antibodies include the components of MB-003 and ZMAb.

READ MORE: Doctor with Ebola gives experimental serum to infected colleague

(PHAC told Global News that it helped to develop ZMapp but it wasn’t involved in any decision-making to administer the treatment. The federal agency developed two of the three components, licensed it to Defyrus, which in turn, sub-licensed it to Mapp. Mapp Pharmaceuticals, for its part, reformulated the treatment with another therapy created by the U.S. Amy Medical Research Institute.)

The antibodies zero in on the Ebola virus, mark any foreign invaders and block out harmful cells. Reports say the drug is derived in part from tobacco plants.

It appears to have helped the two aid workers

The experimental drug was doled out to two people: Samaritan’s Purse physician Dr. Kent Brantly and his colleague Nancy Writebol, who was working with the organization Service in Mission.

Over the weekend, Brantly was admitted to a special isolation treatment and Writebol joined him at Emory University’s hospital in Atlanta.

READ MORE: Why health officials say the Ebola epidemic won’t spread into Canada

Right now, both patients are improving after taking the treatment but we won’t know for sure if it was the experimental therapy that saved them.

They could be recovering on their own, or for other reasons, such as receiving better medical care in the U.S.

A portion of the therapy – the MB-003 – provided 100 per cent protection to monkeys when it was administered right after exposure, according to researchers earlier this year.

The drug hasn’t been evaluated for safety in humans. Brantly and Writebol each had to give consent to using the drug, knowing that it’s only been tested in animals.

(To be clear, Samaritan’s Purse wouldn’t confirm that it was the ZMapp therapy that was administered. Mapp Pharmaceuticals said it couldn’t confirm this detail either.)

It’s only available in limited quantities

Because the drug is in its experimental stages, it’s available only in limited quantities. Zeitlin wouldn’t say how much of the therapy is currently in circulation.

“You can imagine the danger that could potentially put public health workers on the ground in,” Zeitlin told Global.

“We are working as hard as possible with our collaborators to make more as quickly as possible.”

READ MORE: What you need to know about Ebola

There are hundreds of others who have tested positive with Ebola in West Africa, so it’s unclear why the U.S. missionary workers got the drug.

The World Health Organization said it wasn’t involved in the delivery of the therapy, according to CNN. The outlet suggests that the U.S. Food and Drug Administration and its “compassionate use” regulation may be at play. Other reports point to assistance from a National Institutes of Health scientist.

Other drugs are in the works

There are several Ebola vaccines making their way through the pipeline. When reports first surfaced that a single vial of the therapy made its way to Liberia, experts guessed that it could have been out of Vancouver’s own Tekmira Pharmaceuticals. There, researchers are working on using small bits of genetic material called RNA to cling onto the virus and target it for destruction.

But right now, it’s on a temporary hold as the drug makers work through safety concerns.

READ MORE: 5 things to know about the Ebola outbreak amid fears of global spread

Another experimental vaccine being designed out of Winnipeg appears to work if given shortly after exposure to the virus, at least in animal testing, The Canadian Press reported. If it can be pushed through the developmental pipeline, it could be the option of choice for researchers who risk getting infected when working on Ebola in laboratories and health-care workers who can become exposed during outbreaks.

– With files from the Canadian Press and the Associated Press

carmen.chai@globalnews.ca
Follow @Carmen_Chai