Molecular Farming: HIV drug made in GM tobacco enters clinical trials

UK regulators have okayed human trials of a topical anti-HIV microbicide made in greenhouses. The tech is at least 10 times cheaper than conventional bioreactors.
Written by Janet Fang, Contributor

Today in London, UK regulators announced the approval of Europe’s first clinical trial of an anti-HIV product produced in genetically modified tobacco plants. Yep, tobacco.

The phase I trial, carried out at the University of Surrey Clinical Research Centre, will test the safety of the plant-produced antibody designed to stop transmission of HIV when applied directly to the vaginal cavity.

Preliminary results are expected in October. If it proves safe in the 11 participants, the researchers will go on to test the effectiveness of this topically-applied, anti-HIV microbicide.

The active ingredient is an antibody called P2G12 – it recognizes proteins on the surface of HIV to block infection. More specifically, it's a monoclonal antibody made from immune cells for one specific role. It was discovered by private Austrian biotech Polymun.

The GM tobacco plants that churned it out are grown in soil in greenhouses at the Fraunhofer Institute for Molecular Biology and Applied Ecology in Aachen, Germany.

After 45 days, they’re harvested, their leaves are shredded, and highly purified antibodies are extracted. The process yields 5 grams of purified antibody from 250 kg of tobacco.

Advocates of this emerging field – called molecular farmingsay that protein drugs could be made more efficiently and cheaply inside GM crops, since plants are extremely cost-effective protein producers.

  • Mass producing medicines in GM plants uses lower-cost tech than those of biopharmaceuticals made in huge stainless steel fermentation vats containing bacteria or mammalian cells.
  • Production costs could be 10 to 100 times lower than using conventional bioreactors, says Rainer Fischer of the Fraunhofer Institute.
  • The relatively simple manufacturing process could be transferred to developing countries allowing production ‘in the region for the region.’

"This opens the potential for plants to manufacture a range of drugs in the developed, and the developing, world," says project coordinator Julian Ma of St George's University in London.

The biotech medicine is the first plant-produced antibody to be greenlit for clinical testing by Britain’s Medicines and Healthcare products Agency. It took about a year to get that agency’s stamp of approval, according to Nature News, because it wanted assurances that the drugs did not contain allergenic plant sugars or pesticides.

However, no matter how it is produced, P2G12 hasn’t been shown to actually prevent HIV infection in humans, Nature News reports, so a version made by tobacco plants won’t see approval anytime soon.

This trial is the culmination of the EU Framework 6 Pharma-Planta consortium of about 30 academic institutions and small companies. The project was launched in 2004 with about $17 million of EU funding.

Image: tobacco leaf in Germany by Wertdinger via Flickr

This post was originally published on Smartplanet.com

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