By Andrew Pollack
Because of the high prices that drugs can command, medicine ? not
food ? might provide the earliest payoff from genetically engineered
livestock.
A herd of goats engineered to produce a therapeutic human protein
called antithrombin in their milk live on a farm in central Massachusetts.
The animals are owned by a company called GTC Biotherapeutics, which
extracts the protein for use in treating a human hereditary condition in
which people lack antithrombin, which helps keep blood from clotting.

GTC?s drug has already been approved in Europe, and the company is now
conducting clinical trials in hopes of filing for United States approval
early next year.

Other companies, too, are at work on medicines that would be extracted
from a transgenic animal?s milk or blood, saying the approach might be less
expensive than other ways of making protein drugs.

Pharming Group, a Dutch company, has applied for European approval of
a drug made in the milk of transgenic rabbits. Pharmathene, based in
Annapolis, Md., is developing transgenic goats whose milk produces an
antidote to nerve gas.

Hematech, a South Dakota company owned by the pharmaceutical division
of Krin, the Japanese beer company, has developed cows with human immune
systems to produce human antibodies to treat diseases. Other companies and
academic scientists are developing chickens that produce drugs in their eggs
and pigs with organs that would not be acutely rejected if transplanted into
people.

But the path has not been easy, and many companies have had financial
or technological setbacks.

Medical therapies produced in genetically engineered animals would
generally be regulated like other drugs. But the new federal regulatory
guidelines being developed for transgenic animals might also cover at least
the creation and testing of the drug-bearing creatures. And those rules
would apply if the companies tried to sell their animals for food after
their drug-producing days were over.

One ambiguity involves the offspring of genetically engineered
animals, some of which do not inherit their parents? foreign gene and as a
result are genetically normal. There is also the question of what to do
about non-engineered animals that are used simply as surrogate mothers to
carry embryos that have been given foreign genes. The surrogate mothers? own
genetic makeup remains normal.

GTC, at least, says it has no intention of putting any of its animals,
even the non-transgenic ones, into the food supply, to avoid additional
regulatory headaches and the chances of a mix-up. The company incinerates
its genetically altered goats after they die, and it has the non-altered
ones buried by a licensed contractor, according to Thomas Newberry, a GTC
spokesman.

?We think it?s better to deal with all the animals at the same quality
level, at the same access control,? Mr. Newberry said, ?and not try to make
a nickel here and there trying to sell goat cheese.?



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