Mapp’s Ebola Drug Shows Promise, But Making More Will Take Time

Ebola virus

little-known drug set off a media frenzy, with some news reports referring to ZMapp as a “secret serum.”

Mapp Bio, founded in 2003 by longtime colleagues Kevin Whaley and Larry Zeitlin, has just nine employees and has been funded solely by government grants and contracts. Zeitlin told The New York Times’ Andy Pollock earlier this month the urgency of the global health crisis has been “absolutely overwhelming.” They have been working to make the drug available to people as quickly and safely as possible, and are avoiding the limelight by limiting their public comments to terse, occasional statements posted on Mapp Bio’s website.

The antibody constituents used to make ZMapp have been known for years, Saphire said.

ZMapp combines  monoclonal antibodies (blue, green, yellow) that bind to surface of Ebola virus (courtesy TSRI)
ZMapp combines monoclonal antibodies (blue, green, yellow) that bind to surface of Ebola virus (courtesy TSRI)

Each monoclonal antibody binds to a different site on the surface protein of the thread-like Ebola virus, which replicates by attaching itself to the surface of human cells and seizing control. By combining the three antibodies in an optimized formulation, Saphire says ZMapp both neutralizes the virus and alters the immune system to mount its own defenses.

However, the formulation of constituents that became ZMapp was identified for the first time in January, according Mapp Bio. The work has not even been reported in the scientific literature yet, Saphire said.

While the drug was being advanced for medical use, Saphire said scientists working with Ebola kept tabs on what was out there, should it ever be needed—including “that inevitable moment when someone sticks themselves with a needle” tainted with Ebola. She indicated that at the beginning of the year, the scientists at Mapp Bio and Defyrus, a bio-defense company in Toronto, expected to produce what was needed more or less on their own schedule, as the R&D community needed it.

By the time world health authorities realized they were dealing with an unprecedented outbreak of Ebola in West Africa, ZMapp had only been tested in monkeys that had been deliberately infected with lethal doses of the virus. Mapp Bio, through its collaboration with Defyrus and LeafBio, a San Diego commercialization partner, had a limited batch of the drug—apparently enough to treat only a handful of people, according to The New York Times.

“They’ll have to grow another greenhouse full of tobacco plants to make more ZMapp,” Saphire said. Monoclonal antibodies also can be produced in algae and tissue culture, she said, but that would take time too.

While several experimental drugs are

Author: Bruce V. Bigelow

In Memoriam: Our dear friend Bruce V. Bigelow passed away on June 29, 2018. He was the editor of Xconomy San Diego from 2008 to 2018. Read more about his life and work here. Bruce Bigelow joined Xconomy from the business desk of the San Diego Union-Tribune. He was a member of the team of reporters who were awarded the 2006 Pulitzer Prize in National Reporting for uncovering bribes paid to San Diego Republican Rep. Randy “Duke” Cunningham in exchange for special legislation earmarks. He also shared a 2006 award for enterprise reporting from the Society of Business Editors and Writers for “In Harm’s Way,” an article about the extraordinary casualty rate among employees working in Iraq for San Diego’s Titan Corp. He has written extensively about the 2002 corporate accounting scandal at software goliath Peregrine Systems. He also was a Gerald Loeb Award finalist and National Headline Award winner for “The Toymaker,” a 14-part chronicle of a San Diego start-up company. He takes special satisfaction, though, that the series was included in the library for nonfiction narrative journalism at the Nieman Foundation for Journalism at Harvard University. Bigelow graduated from U.C. Berkeley in 1977 with a degree in English Literature and from the Columbia University Graduate School of Journalism in 1979. Before joining the Union-Tribune in 1990, he worked for the Associated Press in Los Angeles and The Kansas City Times.