A clinical trial of a potential Human Immunodeficiency Virus (HIV) drug farmed from genetically modified (GM) tobacco plants has at long last got underway in the United Kingdom. The beginning of the trial follows several years of regulatory negotiations, and is being carried out by the PHARMA-PLANTA consortium, an international group of 28 academic institutions and 4 small companies.
The antiviral preventative P2G12 antibody drug that has been synthesised by GM tobacco plants is being tested on a small number of women in the United Kingdom to establish whether it is safe or not. The first phase of the trial, which kicked off in June, involves testing the safety of the vaginally-applied antibody called P2G12 in 11 healthy women. The results from these tests are expected in October and could bring the science world closer to the development of affordable HIV treatments. The antibody recognises proteins on the surface of HIV to block infection, although it hasn’t yet proven to be effective in humans.
It took such a long time for the UK-based Medicines and Healthcare products Regulatory Agency (MHRA) to give researchers the green light to start the tests as they needed to be 100 % sure that the drugs did not contain any allergenic plant sugars or pesticides. Plants are attractive vehicles for the expression of recombinant pharmaceutical proteins as they are inexpensive and versatile systems, amenable to rapid and economical scale-up. Although the use of GM plants and crops for foodstuffs has proved controversial in Europe, public opinion is more positive towards their use in medicines and vaccines.
The drugs used in the trial are manufactured at a special facility in Aachen, Germany, using a process that yields 5 grammes of purified antibody from 250 kg of tobacco.
This research has the overall objective of using GM plants to cut the costs of drugs that are hard to produce. The scientists hope that this will in turn lead to increasing the availability of modern medicines in some of the world’s poorest regions.