The Ebola virus has sickened 1,711 people in West Africa and killed 932 in the latest outbreak, according to the World Health Organization. The virus has historically killed as many as 90 percent of those who contract it. The current outbreak has claimed the lives of about 60 percent of its victims.
On a small plot of land incongruously tucked amid a Kentucky industrial park sit five weather-beaten greenhouses. At the site, tobacco plants contain one of the most promising hopes for developing an effective treatment for the deadly Ebola virus.
The plants contain designer antibodies developed by San Diego-based Mapp Biopharmaceutical Inc. and are grown in Kentucky by a unit of Reynolds American Inc. Two stricken U.S. health workers received an experimental treatment containing the antibodies in Liberia last week. Since receiving doses of the drug, both patients’ conditions have improved.
Tobacco plant-derived medicines, which are also being developed by a company whose investors include Philip Morris International Inc., are part of a handful of cutting edge plant-based treatments that are in the works for everything from pandemic flu to rabies using plants such as lettuce, carrots and even duckweed. While the technique has existed for years, the treatments have only recently begun to reach the marketplace.
“Producing antibodies in plants is faster and less expensive than traditional manufacturing,” said Mary Kate Hart, an immunology researcher who did pioneering research on Ebola antibodies for the U.S. Army. She now is chief scientific officer for DynPort Vaccine Co.
Few modified-plant derived drugs have made it to market. Pfizer Inc. and Protalix Biotherapeutics Inc.’s enzyme Elelyso, produced in modified carrot cells was approved by U.S. regulators in 2012 to treat Gaucher’s disease. Locteron, an interferon-based hepatitis C drug candidate derived from duckweed, went through Phase 2 trials before its maker, Biolex Therapeutics Inc., declared bankruptcy. Neither drug is a monoclonal antibody and so far there has not been a vegetable-grown antibody approved by regulators, Chen said.
“Tobacco has always had negative press,” said Ebelhar, 66. “But now it may come back to be a benefit to mankind.’ Another tobacco giant-backed company working on biotech drugs grown in tobacco plants is Medicago Inc. in Quebec City, which is owned by Mitsubishi Tanabe Pharma Corp. and Philip Morris. Medicago is working on testing a vaccine for pandemic influenza and has a production greenhouse facility in North Carolina, said Jean-Luc Martre, senior director for government affairs at Medicago. Medicago is planning a final stage trial of the pandemic flu vaccine for next year, he said in a telephone interview. The plant method is flexible and capable of making antibodies and vaccines for numerous types of viruses, said Martre. In addition to influenza, the company’s website says it is in early stages of testing products for rabies and rotavirus.