Tobacco could be back in the good books after it was revealed the plant was being used to manufacture the potentially life-saving experimental drug fighting Ebola.
Two US medical workers who have contracted the deadly disease while in West Africa are being treated with the drug called ZMapp, which has been developed by tiny Californian biotech firm Mapp Biopharmaceutical and has so far only been tested in monkeys. Reports claim the medics’ conditions have improved since being given the drug.
The drug, a cocktail of three antibodies – which works by inactivating virus cells – has been produced in tobacco plants at Kentucky Bioprocessing, part of tobacco giant Reynolds American. Traditionally, antibodies are generated in metal bioreactors. The tobacco-produced drug has been nicknamed “plantibodies”.
“Tobacco makes for a good vehicle to express the antibodies because it is inexpensive and it can produce a lot,” Erica Ollmann Saphire, a professor at The Scripps Research Institute, told Reuters. “It is grown in a greenhouse and you can manufacture kilograms of the materials. It is much less expensive than cell culture.”
The process works by introducing a gene to a carrier virus, which in turn infects the tobacco plant causing it to produce the protein (antibody) coded for by the added gene. The leaves of the plant can then be harvested and the antibody extracted. The antibodies can be extracted just a week after the plant has been infected but the full drug development process is much longer.
The drug and the drug development process still require US FDA approval but there have been calls to roll out the unlicensed drug. But because of limited studies, particularly in humans, questions do remain.
Saphire, who has a grant to study the drug, said researchers didn’t know what to expect in humans. “I was worried, because in the studies in monkeys, you can save all of them if you treat within 24 hours. If you wait several days for disease to develop, you save half.”
There is also controversy over who should have access to the experimental drug with some saying there is a risk West Africans would be used as guinea pigs.
Ebola has killed more than 900 people since the outbreak in West Africa began in February – about 60% of those who have contracted the disease.