A monoclonal antibody drug tested in a clinical trial made all six healthy volunteers violently ill, yet transgenic crop plants with similar drugs are being tested in secret locations and the unsuspecting public are being exposed without their knowledge or consent. Prof. Joe Cummins and Dr. Mae-Wan Ho
The London drug trial that left six healthy volunteers dangerously ill has raised awkward questions on the science and ethics involved in all stages of drug research and development (“Drug trial catastrophe – collapse of science and ethics”, this series). The drug, code named TGN1412, is a genetically engineered humanized monoclonal antibody (MAB) aimed at treating leukaemia and autoimmune diseases such as multiple sclerosis and rheumatoid arthritis. Hundreds of MAB drugs are under development, 18 of which have already been approved by the US FDA, with warnings posted on each and every one of them (“Warnings over FDA approved monoclonal antibody drugs”, this series).
The violent reactions of all six human volunteers injected with TGN1412 serves as a graphic demonstration on how deadly such drugs can be.
In the aftershock of the episode, bioethicists and others have called for tighter regulation of human drug trials and a more cautious protocol. However, no one has raised the alarm over the distinct possibility that the general public might be exposed without informed consent to transgenic crops producing such drugs.
Currently, the MAB drugs approved have mainly been prepared from cell cultures. The cost to the patients would be at least $20 000 to $50 000 per year; the colon cancer drug Erbitux costs $17 000 per month [1]. So, only the wealthy could benefit from such drugs, if at all. Producing the drugs in transgenic farm animals or in crop plants, therefore, promises to greatly reduce the cost of MAB drugs. And plans are afoot to do just that, with reckless disregard for the safety of the general public.
Laboratory mice have already been modified to produce human antibodies and there are efforts to create farm animals producing human antibodies [2]. Human monoclonal antibodies have been produced at relatively high levels in chicken eggs [3]. And humanized MABs have been produced using the yeast Pichia pastoris, ‘glycoengineered’ to express human patterns of glycosylation (carbohydrate chains on proteins) to avoid immunological problems arising from non-human glycosylation [4].
Plant-based production of recombinant antibodies has been discussed extensively. A review published in 2003 [5] reported that six plant-derived antibodies have been developed as human therapeutics. The drug, Avicidin, developed by NeoRx and Monsanto, had some anticancer effect on colon cancer; but it caused severe diarrhoea and was withdrawn. A plant-derived antibody CaroRx produced in tobacco claims to reduce tooth decay by preventing adhesion of the bacterium Streptococcus mutans. A MAB targeting the cancer-antigen CEA was produced in tobacco, pea, rice and wheat. A humanized MAB recognizing herpes simples virus 2 was produced in soybean. Tobacco plants were transformed with a viral vector to produce antibodies targeting non-Hodgkin’s lymphoma. Finally, a MAB produced in tobacco targeted human chorionic gonadotropin, and was intended for use in contraception, pregnancy detection and therapy of tumours [6]. Plants have been transformed to produce prophylactic antibodies against rabies and other disease conditions [7].
We have drawn attention to the hazards of producing genetically modified vaccines and therapeutic antibodies. The main threat is the genetic pollution of major food crops resulting in food that is toxic [8]. Humanized MABs structured to attack herpes virus or regulate the human immune system were to be produced by transgenic strains of the green alga Chlamydomonas in large plastic tubes near a beach in Hawaii Chlamydomonas is a common soil microbe so the nature and location of the production facility would risk spreading the transgenic strains and the human genes also to soil microbes [9].
Molecular pharming (producing pharmaceuticals in transgenic crops) is turning into a new battlefront in the struggle of the global civil society against transgenic crops. Too many governments of industrialised countries appear to be prepared to allow biotech corporations to contaminate our food supply with un-prescribed and dangerous drugs [10].
There have been at least 29 field tests of transgenic crops known to be producing antibodies, but the actual genes have been deemed confidential business information (CBI). The crops modified include maize and soybean; and the companies testing the transgenic crops are Prodigene, Monsanto and Agracetus, among others. The field releases were in Hawaii, Nebraska, Wisconsin, Iowa, Indiana Minnesota, Puerto Rico, Texas and other states [1]. Other crops and MABs may have been tested, but designated CBI, as are the actual locations of such tests, and no effort has been made to notify bystanders and neighbours that are likely to be directly exposed to the drugs. People may be exposed to MABs from transgenic crops by pollen, dust debris from leaves, stems and flowers, and from polluted surface and groundwater. Once the MAB genes escape to fertilize neighbouring crops, they will persist within the contaminated crops, by virtue of simple Hardy-Weinberg equilibrium in elementary population genetics!
There is no case for using crop plants in the open field to produce these drugs, as they could easily be produced in plant cell culture under fully contained conditions.
The secretive field trials should never have been allowed, as they are exposing people, without their knowledge or consent, to drugs that could become life-threatening, as the London drug trial so vividly demonstrated.
The location and nature of current and previous field trials should be made public now before any more damage is done, and all further field trials should be banned.
Article first published 10/04/06
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