Jeffrey Turner, president and CEO of Defyrus, discussed the Ebola outbreak and ZMapp’s potential role on Monday during a web seminar as part of National Biotech Week.
ZMapp is a blend of three monoclonal antibodies that interfere with how the Ebola virus is able to attach and enter a host cell.
"Initially, the concept was we needed couple of hundred courses of therapy. Clearly we need more than that," Turner said.
Tens of thousands of doses are likely needed.
"Is it going to happen next year? Probably. We're moving heaven and earth to scale up manufacturing and produce those types of numbers in 2015."
Turner outlined some challenges involved in the production and development of ZMapp and its possible role in the outbreak:- The infection rate is not stopping despite a huge amount of activity around the world. Previously, the Ebola virus infected thousands of people — a small, short-term market.
- Doctors need enough monoclonal antibodies for the treatment to work but it has to come at reasonable cost. "The magic number is three," he said.
- Scale-up is also costly.
Turner credited the Public Health Agency of Canada and the U.S. army, which both invested heavily in laboratories and infrastructure to test potential monoclonal antibodies in animal models, validated by third parties and published the findings before companies like Defyrus and MappBio in the U.S. entered the picture.
The U.S. National Institutes of Health brought MappBio and Defyrus together in January in Washington after realizing that while the two groups' experimental drugs worked well separately, together they were better.
Two of the antibodies were originally developed at the National Microbiology Laboratory in Winnipeg and one was developed at the U.S. Army Medical Research Institute of Infectious Diseases in Frederick, Md.
Small biotech firms like Defyrus are nimble and not afraid to fail in drug development — an area with many more failures than successes, Turner said. But such firms are able to build on the successes to drive manufacturing, put together intellectual property portfolios and use their networks to get the drug to different areas of the world where it’s needed, he said.
In Kentucky, scientists are using special tobacco plants to produce large amounts of the antibodies, which are then extracted. Since plants take time to grow, they’re also using large reactors to produce some more quickly.
Turner acknowledged that his company has been criticized for not producing more doses, but said more resources have been brought in.
The World Health Organization has authorized the use of some experimental treatments during the outbreak in West Africa. None have yet been tested for safety and efficacy in clinical trials in humans.