NEW YORK -- It's an eye-catching angle in the story of an experimental treatment for Ebola: The drug comes from tobacco plants that were turned into living pharmaceutical factories.

Using plants this way -- sometimes called "pharming" -- can produce complex and valuable proteins for medicines. That approach, studied for about 20 years, hasn't caught on widely in the pharmaceutical industry.


While most of the work in this area uses a tobacco plant, it's just a relative of the plant used to make cigarettes.

"It's definitely not something you smoke," said Jean-Luc Martre, a spokesman for Medicago, a Canadian company that's testing flu vaccines made with tobacco plants.

Medicago has a new production facility in Research Triangle Park, North Carolina. Once approved by federal authorities, it's expected to be able to make 30 million doses of seasonal flu vaccine a year, or 120 million vaccine doses to fight a major outbreak of "pandemic" flu if the government requests it.





That experimental treatment, called ZMapp, uses proteins called antibodies, and is designed to inactivate the Ebola virus and help the body kill infected cells. It hasn't been tested in people but had shown promise in animal tests, so it was tried in three people sickened by Ebola in West Africa -- two U.S. aid workers and a Spanish missionary priest, who later died.


In general, the idea behind pharming is to slip the genetic blueprints for a particular protein into a plant and let the plant's protein-making machinery go to work. Then the protein can be extracted from plant tissues. While tobacco plants are a mainstay of such work, proteins also have been produced in other plants, such as safflower and potato.

In fact, the only medicine made this way that the federal government has approved for general use in people is made in a laboratory from cells of carrot plants. It treats a genetic illness called Gaucher's disease. The drug was approved in 2012 by the Food and Drug Administration.


The lack of any stronger track record for approved drugs in the United States is a key reason why the plant-based technology hasn't been embraced more fully, Locwin said. That's despite the fact that it offers benefits like lower cost than the standard approach of using vats of cells from mammals to churn out complex proteins, Locwin said.

Some companies use cells from bacteria instead, but they can't always produce the complicated proteins that drug companies need, he said. The plant-based approach "has a tremendous amount of promise, but it doesn't yet have the FDA blessing across the board to be able to say this is successful" and a proven way to get a drug to market, he said.


Plant-based drugs have attracted the attention and funding of the federal government, however, as a fast and cheap approach to make a lot of vaccine material in case of terrorist attacks, said Daniel Tuse (pronounced too-SAY'), a consultant and managing director of Intrusept Biomedicine, which also works with tobacco plants in Owensboro.

