Researchers focus on drug-producing plants

Genetically engineered crops raise concerns


Joe Williams, a Virginia tobacco farmer, has been forced to cut his production nearly in half over the past three years as people have kicked the smoking habit. But he is hoping that a small experimental plot he just planted will hold the key to his staying on the farm. That tobacco has been genetically engineered to produce not cigarettes but pharmaceuticals.

Plants containing drugs could represent a new high-priced crop. "If we can actually find a medical use for tobacco that saves lives, what a turnaround for the much-maligned tobacco plant," said Christopher Cook, chief executive of ToBio, a company recently formed by Virginia tobacco farmers like Williams to grow drugs in cooperation with the CropTech Corp. of Blacksburg, Va.

The production of drugs in genetically altered plants - called molecular farming or biopharming - seems poised to represent the next wave in agricultural biotechnology. Until now, efforts have mainly been directed at protecting crops from pests and improving the taste and nutrition of food.

But just as the production of bioengineered foods has been controversial, molecular farming is raising safety and environmental concerns.

Chief among them is that drugs might end up in the general food supply, either because crops or seeds are misrouted during processing or because pollen from a drug-containing crop in an open field fertilizes a nearby food crop. What if insects eat the drug-containing plants or if the drug leaks into the soil from the roots?

About 20 companies worldwide are working on producing pharmaceuticals in plants, according to the Bowditch Group, a Boston consulting firm.

A handful of such drugs are being tested in human clinical trials, including vaccines for hepatitis B and an antibody to prevent tooth decay.

And there have been dozens of field tests like the one on Williams' farm, aimed at seeing if products from hemoglobin to urokinase, a clot-dissolving drug, can be grown in crops like corn, tobacco or rice.

In a closely related effort, companies are also trying to use plants to produce industrial chemicals.

Proponents say that farming for pharmaceutical proteins would be far cheaper than the current practice of producing these drugs in genetically modified mammalian cells grown in vats.

That could lower the price of drugs produced by biotechnology, some of which now cost tens or even hundreds of thousands of dollars a year per patient.

In some cases, the drugs would not even have to be extracted from the plant. Scientists are testing edible vaccines in which people would be protected from diseases by eating genetically engineered foods.

As these crops get closer to market, regulators are trying to figure out how to ensure their safety. Last month, the Food and Drug Administration and the Agriculture Department held a public meeting in Ames, Iowa, to discuss the issue.

The regulators say some safeguards are already in place. To minimize environmental risks, all field tests of drug-producing plants must receive government permits, while some field tests of other modified crops require only that the government be notified, said Michael Schechtman, biotechnology coordinator for the Agriculture Department.

In addition, the distance by which the drug-bearing plants must be isolated from other plants to prevent cross-pollination is double the usual distance used by seed companies to assure purity of their seeds, he said. And although genetically modified food crops are often deregulated after the product becomes commercial, he added, the planting of drug-containing crops is likely to be regulated forever.

But Norman C. Ellstrand, a professor of genetics at the University of California at Riverside and an expert on pollen flow, said that long-distance pollen flow is poorly understood and that the appropriate isolation distance for drug-producing plants would depend on the particular crop and drug. "It's just not clear that setting a double distance is going to solve everything," he said.

Indeed, biopharming lies on the border of medical biotechnology, which has been largely free of controversy, and food biotechnology, which has been beset by protests.

Some executives in the fledgling industry say that because medicines clearly help people, their activity is not generating the same kind of resistance as the production of genetically modified food crops.

In addition, they say, drugs are tested and regulated far more stringently than biofoods. "It's being received entirely differently," said William White, president of Integrated Protein Technologies, a unit of the Monsanto Co. that is trying to grow drugs in corn.

But critics of agricultural biotechnology say that such companies, which underestimated the public reaction to bioengineered foods, are repeating the mistake. Michael Hansen of Consumers Union, for one, said the public had no idea about the work being done to produce drugs in plants.

"Once they have an idea, the thought of putting drugs in plants is not going to go over well," he said.

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