A small number of women in the UK are to be tested with an antiviral drug synthesised by genetically modified plants to establish its safety, bringing closer the prospect of affordable modern medicines for the developing world.
The human trial is taking place in Guildford at the clinical research centre of the University of Surrey and has been approved by the Medicines and Healthcare products Regulatory Agency (MHRA), the UK licensing body.
The researchers hope it can be used to prevent HIV infection. The research is truly innovative, however, because it demonstrates it is possible for similar therapeutic molecules (monoclonal antibodies) to be produced to the high standards needed for human use relatively cheaply in plants.
Launched seven years ago, the Pharma-Planta project aims to use GM plants to significantly reduce the cost of drugs that are hard to produce. The researchers’ objective is to increase the availability of these modern, often highly effective, medicines in the poorest countries of the world.
“The driver was to produce these medicines economically and at a level that would satisfy global demand,” said the joint co-ordinator of the European Union-funded project, Professor Julian Ma from St George’s University, London.
Similar monoclonal antibody medicines are synthesised expensively in fermentation vats containing bacteria or mammalian cells. Pharma-Planta, by contrast, produced the anti-HIV molecule in genetically modified tobacco plants grown in soil in greenhouses in Germany. After 45 days, the plants were harvested, their leaves shredded and “highly purified antibodies” were extracted.
This method is between 10 and 100 times cheaper than the conventional process, said Professor Rainer Fischer of the Fraunhofer Institute for Molecular Biology and Applied Ecology in Aachen, Germany, where the plants were grown.
The researchers say there is little risk of such GM plants contaminating other crops or spreading because they would not be grown on anything like an agricultural scale and are contained.
“The approval from the MHRA for us to proceed with human trials is an acknowledgement that monoclonal antibodies can be made in plants to the same quality as those made using existing conventional production systems. That is something many people did not believe could be achieved,” Professor Ma said.
The trial is designed only to prove the safety of the antibody, named P2G12, at different doses. Eleven healthy women volunteered to take part in the trial and so far two of them have been given the medicine, with a third woman given a placebo. Much larger trials in women at risk of contracting HIV would be necessary to test whether the drug could prevent becoming infected.