Cures On the Cob

By Margot Roosevelt/San Diego

The scraggly cornstalks sprouting from pots in Andy Hiatt's laboratory don't look particularly unusual. But woven into their DNA is a tiny strip of mankind: a human gene that codes for an antibody to a sexually transmitted disease--genital herpes--that afflicts some 60 million Americans. When the corn plants mature and produce kernels, Hiatt's company, Epicyte Pharmaceutical of San Diego, hopes to turn them into a topical gel for herpes.

And that's just for starters. Epicyte is one of a host of biotech companies that have seized on the information in the map of the human genome--a map that was officially declared complete last month--to create all manner of plant-based pharmaceuticals. Researchers have launched more than 300 trials of genetically engineered crops to produce everything from fruit-based hepatitis vaccines to AIDS drugs grown in tobacco leaves. They call this biopharming.

Critics--and there are many--have another name for it. They call it Pharmageddon. Environmentalists are worried that the unnaturally combined genes, when loosed upon the ecosphere, will spread like genetic kudzu. Consumer advocates, who have never warmed to today's genetically modified foods, fear that plant-grown drugs and industrial chemicals will end up on their dinner tables. Hoping to head off a public revolt, the Federal Government is putting the finishing touches on new regulations aimed at reassuring the grocery industry that human-based crops will not contaminate the food supply.

But the proposed rules are not satisfying the critics or slowing the biopharmers. Open-air trials of pharmaceutical crops have taken place in 14 states, from Hawaii to Maryland. A Texas firm is selling a corn-bred enzyme that stimulates insulin production in diabetics. Clinical trials have begun for experimental crop-grown drugs to treat cystic fibrosis, non-Hodgkin's lymphoma and hepatitis B. "Molecular farming represents the pharmaceutical industry's best opportunity to strike a serious blow against such global diseases as AIDS, Alzheimer's and cancer," says Francois Arcand, president of the Conference on Plant-Made Pharmaceuticals, held in Quebec City earlier this year.

What's driving this effort to morph fields into drug factories? In a word: cost. In the past decade, the DNA revolution has spawned a generation of drugs made from human antibodies, the proteins that white blood cells use to defend the body against disease. Today such "biologics" are cultivated in huge fermentation vats, often by painstakingly planting cloned human cells in such unlikely breeding sites as the ovary cells of Chinese hamsters. Building one of these sophisticated biofactories can take as long as seven years and cost up to $600 million.

Achieving the same results through biopharming--splicing antibodies into the genetic fabric of plants, growing them in fields and extracting and purifying them--could cut costs by half. "If you don't have to spend half a billion, then more products can advance to the marketplace," says Arizona State University researcher Charles Arntzen. The opportunities, he points out, are not limited to human drugs. Arntzen foresees rich markets for plant-grown vaccines to protect fish and poultry against diseases now being treated--and in many cases overtreated--with conventional antibiotics.

So far, more than two-thirds of plant-based medicines are being tested in corn--a plant whose genetics is well understood. But the perils of using food crops became clear last December when the U.S. Department of Agriculture (USDA) ordered the incineration of 500,000 bushels of soybeans in Aurora, Neb. The soybeans, from a plant used in everything from baby food and margarine to ice cream, were inadvertently mixed in a silo with corn that was genetically engineered by a Texas firm, ProdiGene Inc., to produce a vaccine against pig diarrhea. "Drugs have side effects," says Jean Halloran of the Consumers Union. "They should not turn up in our cornflakes."

The pig-diarrhea incident rattled the industry. Some major players, among them Dow and Monsanto, are steering clear of the Farm Belt, preferring to grow their pharmacorn in isolated areas of Arizona, California and Washington State. Even so, the USDA--under pressure from Midwestern politicians who dream of biopharm Silicon Valleys in Iowa--has stopped short of restricting biopharming in major corn-growing states. Its new rules would step up inspections of biopharms and expand the buffer zone between genetically modified corn and food crops to a mile. But opponents say that's not wide enough to prevent cross-pollination, and a coalition of 11 environmental groups is filing suit against the Agriculture Department. They want to ban the use of food crops for pharmaceutical uses and restrict the plants to greenhouses. If such measures were enforced, argues Jonathan McIntyre, chief scientist for Monsanto Protein Technologies, "it would set back the industry 12 to 20 years."

At Epicyte's spotless laboratory, Hiatt is taking no chances. Tiny tobacco leaves injected with herpes-antibody genes fill the incubators--a backup, he says, in case corn is outlawed. And the company is branching out, developing plant-grown antibodies to fight respiratory syncytial virus, treat Alzheimer's, battle weaponized Ebola and even attack sperm--a kind of biopharm birth control.

By the end of the decade, biopharmaceuticals are projected to grow into a $20 billion industry. But how many of the new drugs will be manufactured in living plant-factories remains uncertain. "There has been an emotional response to the technology," says Hiatt. "But if we can bring down the cost of treating these diseases, the drawbacks compared with the benefits will be minuscule."