Making ZMapp: Production of Experimental Drug to Treat Ebola Is Now A Priority

Randi Hernandez

Randi Hernandez was science editor at BioPharm International from September 2014 to May 2017.

Manufacturing drugs from biological sources sometimes can't be rushed, even when a rare disease becomes more widespread.

The rapid onslaught of the Ebola virus and the fact that there are no treatments readily available to fight the outbreak has caused many to question why there were not more drug therapies on hand or even in development to treat this devastating virus. The one treatment option, ZMapp, which is being developed by Mapp Biopharmaceutical Inc., LeafBio, and Defyrus Inc., had not been tested in human trials before it was used to treat two American aid workers, according to .

ZMapp is a biological product, and consists of Defyrus’ ZMAb antibody portfolio and Mapp’s antibody MB-003. MB-003 was developed in collaboration with the National Institutes of Health and the Defense Threat Reduction Agency, according to a .

The Centers for Disease Control and Prevention it is still too early to know if ZMapp is truly efficacious, and even if it is, the manufacturer has already distributed all of the doses that were produced. “The challenge that many people don’t appreciate is that our plans were to scale up this drug for 2015 and even then, small amounts for clinical trials,” said Jeffrey D. Turner, president and CEO of Defyrus, to . “What’s really happened with this outbreak is it’s caught us in a position where we didn’t have enough ZMapp available because no one would have bought it.”

Drug manufacturers need to have an incentive to create new therapies, and the money usually lies within the patient population. As a result, many infectious tropical viruses are not researched as heavily. Despite the passage of the FDA Priority Review Program, which became law in 2007 and was intended to incentivize development of neglected tropical diseases, manufacturers want blockbusters—and treating rare viral diseases is not always a priority for financial reasons.

In addition, the manufacture of ZMapp, because it relies on biotechnology and deals with antibodies in live cells, is a lengthy process. Currently, the antibodies for ZMapp are being produced in a biologically engineered tobacco plant called Nicotiana under an existing collaboration with Kentucky Bioprocessing. The human proteins could also be made in animal cells (such as Chinese hamster ovary cells) in large bioreactors, but there is no guarantee that the product could be used safely without being tested extensively first and it still could take months to produce the antibodies. In short, there really is no smart way to speed up production of the drug given the sensitive environment of the living cells.

There have also been some regulatory delays in ZMapp’s production, noted a recent article. However, the Biomedical Advanced Research and Development Authority has given Mapp a $25-million contract to start human clinical trials. Two other companies, Tekmira and Biocryst Pharmaceuticals, also have therapeutic candidates for Ebola in early development. Johnson & Johnson and GlaxoSmithKline both have Ebola vaccines in the works as well.