Revelations About ZMapp Applicable To Future Ebola Drugs

New research published this week by Scripps Research Institute (TSRI) gives scientists new insight into the mechanics of ZMapp, an experimental Ebola treatment, which might direct and influence future Ebola drug discoveries.

ZMapp, discovered and developed by Mapp Pharmaceuticals, has been used on an experimental basis to treat seven patients in the U.S. Four of these patients have survived, but scientists do not yet understand enough about the drug to know what role ZMapp played in those patients’ recovery.

A team of TSRI scientists led by Andrew Ward and Erica Saphire used an electron microscope to get a good look at how the three antibodies which make up ZMapp attach to the Ebola virus and what function they serve.

TSRI reports that two of the antibodies bond to the virus near its base and prevent the virus from entering the cell. The other antibody bonds to the top and functions as a signal to the body’s immune system and leads the patient’s natural defenses to the site of the infection.

Luckily, these two areas on the virus are — as yet — unaffected by the almost 300 mutations of the virus reported from West Africa.

According to Ward, “Now that we know how ZMapp targets Ebola, we can compare all newly discovered anti-Ebola antibodies as we try to formulate an even better immunotherapeutic cocktail.”

Saphire speculated to the Los Angeles (LA) Times whether or not one of the two antibodies which attach to the base of the virus might be redundant.

The three antibodies are grown using tobacco plants, and the process takes months to complete. The delay has frustrated health workers who want to rush a potentially successful treatment to West Africa where it is most needed.

Robin Robinson, director of the U.S. governments Biomedical Advanced Research and Development Authority (BARDA) told the LA Times that Mapp Pharmaceuticals “is working with Kentucky BioProcessing to produce additional doses that would be available next year.”

Last month, Charles Arntzen, credited creator of ZMapp, told Al Jazeera America that the company would be lucky to produce 1000 doses by the end of the year, not nearly enough to help all of those struggling to fight the virus.

Clinical trials to test the true efficacy of ZMapp are slated to begin early next year, and TSRI researchers say that only then will we truly understand the function and success of the drug.

Saphire explains, “If you want to know whether something works, you need a controlled laboratory study.”