The move marks an advance in the emerging field of molecular farming, which may offer a cheaper way of making complex biotech drugs and vaccines than traditional factory systems.
Following a green light from regulators, the monoclonal antibody is being tested in a small study involving 11 healthy women in Britain. It is designed for use as a vaginal microbicide to prevent HIV transmission during sex.
If the Phase I study is successful, larger trials will follow and researchers envisage the new antibody, P2G12, will be combined with others in a microbicide offering broad protection against HIV/AIDS.
The trial is a milestone for the Pharma-Planta project which was launched in 2004 with 12 million euros ($16.8 million) of European Union funding.
At the moment, costly antibody drugs, such as Roche’s cancer treatments Herceptin and Avastin, are produced in cell cultures inside stainless steel tanks.
Advocates of molecular farming believe such protein drugs could be made more efficiently and cheaply inside genetically modified (GM) crops, since plants are extremely cost-effective protein producers.
Project co-ordinator Julian Ma, professor of molecular immunology at St. George’s, University of London, told reporters on Tuesday the green light for the trial was an acknowledgement that antibodies could be made in plants to the same quality as those made in factories.
The antibody being tested was discovered by private Austrian biotech Polymun.
Ma said he hoped the lower-cost technology would eventually be transferred to poor countries, giving them access to biotech medicines for cancer, rheumatoid arthritis and some infections that are currently “horribly expensive.”
“This opens the potential for plants to manufacture a range of drugs in the developed, and the developing, world,” he said.
Rainer Fischer, head of the Fraunhofer Institute for Molecular Biology and Applied Ecology in Aachen, Germany, where the tobacco plants were grown, said production costs would be at least 10 times lower than using conventional bioreactors.
Genetic modification remains a sensitive topic in Europe, where there is widespread opposition to GM foods.
But Ma said he did not expect public resistance to using GM plants in medicine, given the plants would be grown in contained greenhouses and that tobacco is not part of the food chain.
Still, major drugmakers may be reluctant to rush into the disruptive new technology, given their existing investment in stainless steel bioreactors which have recently seen a marked increase in yields, thanks to improved efficiencies.
Some large companies have been looking at ways to make complex protein drugs in plants but molecular farming has yet to deliver its first commercial product.
The closest is a Gaucher disease drug from Israel’s Protalix BioTherapeutics and Pfizer , which is produced in a culture of carrot cells — rather than in whole plants — and has been filed for approval.
US regulators said in February they needed more data on the product before deciding whether to give it a green light.
Bayer is also conducting research in the United States on tobacco-based treatment for non-Hodgkin’s lymphoma, a type of blood cancer.
