Anti-HIV drug made by GM plants begins trials in humans

An antiviral drug synthesised by genetically modified plants is being tested on a small number of women in the UK to establish its safety, bringing closer the possibility of cheap modern medicines for the developing world.

The drug's developers hope it can be used to prevent HIV infection, but the real breakthrough is that the research demonstrates it is possible for similar molecules – known as monoclonal antibodies – to be produced relatively cheaply in plants to the high standards needed for their use in humans.

The human trial has been approved by the UK licensing body, the Medicines and Healthcare products Regulatory Agency (MHRA), and is taking place in Guildford at the clinical research centre of the University of Surrey.

Pharma-Planta is a project launched seven years ago with the objective of using GM plants to slash the cost of drugs that are hard to produce. The scientists' aim is to increase the availability of these modern medicines – which are often highly effective – in the poorest countries of the world.

Access to medicines in the developing world is extremely limited. The World Health Organization estimates that 23 million infants worldwide do not get adequate basic immunisation and 1.7 million children under five die from vaccine-preventable diseases.

"The driver was to produce these medicines economically and at a level that would satisfy global demand," said Professor Julian Ma from St George's University, London, who is the joint co-ordinator of the European Union-funded project.

Many medicines are synthesised at great expense in fermentation vats containing bacteria or mammalian cells. By contrast Pharma-Planta produced the anti-HIV monoclonal antibody in GM tobacco plants grown in soil in greenhouses in Germany. After 45 days, they were harvested, their leaves were shredded and "highly purified antibodies" were extracted.

The researchers say there is little risk of such GM plants spreading or contaminating other crops because they are contained and would not be grown on anything like an agricultural scale.

Ma said it was "a red letter day" when they received the go-ahead from the drugs regulator. "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," he said.

Eleven healthy women have volunteered to take part in the trial and two of them have been given the antibody so far, with a third woman having been given a placebo. The trial is designed only to demonstrate the safety of the antibody, called P2G12, at different dosages. Much bigger trials in women at risk of contracting HIV would be necessary to test whether it could prevent infection.
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Economic Importance of Bats in the 'Billions a Year' Range

McCracken's findings are published in the April edition of Science. McCracken conducted his study with Justin Boyles of the University of Pretoria in South Africa, Paul Cryan of the U.S. Geological Survey and Thomas Kunz of Boston University.

Since 2006, more than a million bats have died due to a fungal disease called White-Nose Syndrome (WNS). At the same time, several migratory tree-dwelling species are being killed in unprecedented numbers by wind turbines. This hurts the economy because bats' diet of pest insects reduces the damage the insects cause to crops and decreases the need for pesticides.

In fact, the researchers estimate the value of bats to the agricultural industry is roughly $22.9 billion a year, with the extremes ranging as low as $3.7 and $53 billion a year.

"These estimates include the reduced costs of pesticide applications that are not needed to suppress the insects consumed by bats. However, they do not include the downstream impacts of pesticides on humans, domestic and wild animals and our environment," said McCracken. "Without bats, crop yields are affected. Pesticide applications go up. Even if our estimates were quartered, they clearly show how bats have enormous potential to influence the economics of agriculture and forestry."

According to the researchers, a single colony of 150 big brown bats in Indiana eat nearly 1.3 million insects a year -- insects that could potentially be damaging to crops.

WNS infects the skin of bats while they hibernate. Some species such as the little brown bat are likely to go extinct in parts of North America. The disease has quickly spread from Canada to Tennessee, Missouri and Oklahoma and actions to slow or stop it have proven unsuccessful.

It is unknown how many bats have died due to wind turbines, but the scientists estimate by 2020, wind turbines will have killed 33,000 to 111,000 annually in the Mid-Atlantic Highlands alone. Why migratory tree-dwelling species are drawn to the turbines remains a mystery.
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