Pharming' to Find Cures Takes Root
Biotech companies are developing crops to fight human disease. But critics
balk
Associated press
By Paul Elias
October 28, 2001
In a greenhouse tucked away in Indianapolis flourishes corn
being engineered to provide the active ingredients in gels that fight
herpes and kill sperm.
On 27 acres of Kentucky farmland grows tobacco that someday may actually
help fight cancer.
And in the tiny Northern California farming town of Live
Oak, rice laced with disease-fighting antibiotics usually found in mother's
milk sprouts on a 10-acre paddy.
It's called molecular farming, and it's blossoming at biotechnology
start-ups across the country.
The idea is to implant human genes into crops to grow disease-fighting
proteins, which can then be extracted and turned into profitable drugs
and therapies.
Some companies trick crops into accepting human genes spliced
into the plants' DNA. Seeking to produce a contraceptive, Epicyte Pharmaceuticals
Inc. is splicing into corn a genetic defect found in some women with the
aim of making the plant generate a protein that kills sperm.
Another company, Large Scale Biology Corp., sprays plant viruses injected
with human genes onto tobacco plants; the resulting infections produce
cancer-fighting human antibodies.
Molecular farming offers an elementary yet revolutionary proposition:
It seeks to "grow" human therapies in the fields and crack the antibody
drug market, which had $2 billion in sales last year and is expected to
grow to $8 billion by 2004.
Some biotech companies have been able to grow antibodies
-- disease-fighting proteins that protect the body -- in labs and turn
them into drugs. Proponents say molecular farming could significantly
cut the costs of developing such substances.
Ten genetically engineered antibody drugs are on the market
today, all developed using mice. Among the best known is Herceptin, which
is used in treating some breast cancers and made by Genentech.
It took Genentech, Novartis, MedImmune and other companies decades of
research and hundreds of millions of dollars to convince the Food and
Drug Administration that these drugs would not harm humans. All 10 are
mass-produced in state-of-the-art laboratories in huge vats -- called
bioreactors -- after the antibodies have been extracted from the mice
where they are manufactured.
Typically, it takes $100 million to $500 million and up
to 10 years to discover, develop and deliver a single such drug.
Molecular farmers think they can get their drugs to market
for as little as $50 million by using fields instead of bioreactors to
grow the raw material -- and because less costly laboratory processes
could be used to refine the useful proteins for use in medicines.
"We can inexpensively produce a huge number of high-quality
plants to manufacture human proteins," said Robert Erwin, chief executive
of Vacaville, Calif.-based Large Scale Biology.
ProdiGene Inc., based in College Station, Texas, is developing eight human
therapies, including a hepatitis B vaccine. It also says it won't need
an elaborate infrastructure to produce its drugs.
ProdiGene's main manufacturing tool -- corn -- is fueled by sun, air and
water, said its chief scientist, John Howard.
But technological obstacles loom. Few of these plant-generated
proteins have been tested in people.
One of the furthest along, Large Scale Biology's non-Hodgkin's lymphoma
test at Stanford University, involves just 16 subjects and is in Phase
I testing, the first and smallest of the three human trials required by
the FDA for any drug.
"Molecular pharmers" hope FDA approval for wider trials will be easier
because their drugs don't involve another animal species, and so there
is no danger of animal viruses infecting people.
But they must not only convince the FDA that their drugs are safe and
effective. They must also show the Department of Agriculture that their
transgenic crops aren't likely to contaminate the food supply.
"Production of pharmaceutical compounds in crops is intriguing
and possibly lucrative in the long run," said C.S. Prakash, who manages
the Center for Plant Bio Research at Tuskegee University in Alabama. "It
does take many years of research and the long regulatory process involving
FDA and USDA to get their products out."
Both agencies began meeting this past summer to draw up
guidelines to better regulate biotechnology farming. Nothing formal has
been proposed. Currently, a USDA permit is required to grow transgenic
plants outdoors, and the crops must be isolated from fields that produce
food.
Activists who reject genetically modified food as unsafe will be watching
closely, determined to keep up the pressure for strict safety standards.
In September, Greenpeace protesters donned biohazard suits and carried
10-foot-tall syringes in front of a farm growing rice for Applied Phytologics
Inc., which is experimenting with growing human proteins found in mother's
milk.
The company's USDA-approved buffer zone was a 4-foot row of traditional
rice, and Chief Executive Officer Frank Hagie said the experiment wouldn't
harm humans, plants or animals. But Greenpeace said the impact of the
transgenic rice hadn't been studied, and contamination couldn't be ruled
out.
"There are environmental concerns as well as unknown consequences,"
Jeanne Merrill of Greenpeace said.
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