OT: OT: Transgenics

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BUSINESS BIOSCOPE Biotech Firms Transforming Animals Into Drug-Producing Machines / Transgenic creatures carry human DNA that produce proteins Tom Abate

Jan. 17, 2000 San Francisco Chronicle FINAL Page B1 ( Copyright 2000 )

Several biotech firms in the United States and Europe are giving new meaning to the slogan "Got milk?"

These companies have spliced a few human genes into the DNA of goats, sheep, pigs and other mammals.

These human genes are designed to produce, in the animal's milk, a specific therapeutic protein to combat a human disease.

For instance, the animal might be bioengineered to produce a protein to treat hemophilia.

The therapeutic protein would be extracted from the milk, purified and packaged as a drug.

Putting genes from one creature into another is called transgenics. In short, these transgenic animals are being groomed as four-legged drug factories.

Transgenic drug production remains experimental.

The standard way to brew drugs is in huge stainless steel vats in a fermentation process that makes protein factories look like wineries. Proponents of transgenic production say animals will ultimately provide less expensive factories.

Last week at a health science conference in San Francisco, a Massachusetts firm called Genzyme Transgenics announced an important milestone in the process of getting transgenic animals approved as protein therapy producers.

The company announced positive results from a Phase III trial of an anti-clotting protein derived from the milk of a transgenic goat.

Phase III trials are usually the last experiment before a company seeks Food and Drug Administration approval to sell a product. But because this process is so novel, Genzyme Transgenics is running a second Phase III study to gather additional safety data.

"Toward the end of the year, we would expect to have the two studies in hand," said Genzyme Transgenics CEO Sandra Nusinoff Lehrman, who must ultimately decide whether to ask the FDA to OK the first therapeutic protein produced from a transgenic animal.

Genzyme Transgenics has half a dozen similar trials under way, a little earlier in the testing process, to determine whether goats, rabbits and cows can reliably produce high-quality therapeutic proteins in their milk.

PPL Therapeutics in the United Kingdom is experimenting with transgenic sheep's milk to produce protein drugs for cystic fibrosis and hemophilia.

Pharming NV, a biotech firm in the Netherlands, is testing whether transgenic rabbits, cows and mice can produce a variety of human proteins for stomach ailments and other bleeding disorders.

Bill Drohan, a senior research director for the American Red Cross, is collaborating with Pharming to create transgenic pigs to make the protein raw material for a new surgical bandage.

Drohan explained that human blood contains a protein called fibrinogen, which forms thin tendrils across a wound to trap blood and form a clot.

"If you look at a fresh scab, 90 percent of it is fibrinogen," Drohan said.

The idea behind the bandage is simple: Smear fibrinogen on a bandage and slap it on a wound. "Early tests show this can stop any type of bleeding in 15 seconds," he said, even gushing wounds that normally prove fatal.

Not surprisingly, the U.S. Army would love to put such miracle bandages in every medical field kit. The problem, Drohan said, is that today fibrinogen is extracted from human plasma, and the Red Cross can't imagine getting enough plasma donors to meet the likely demand.

Enter the transgenic pigs. "The value of transgenic animals is that they can make large quantities of safe material at reasonable costs," Drohan said.

Producing protein drugs through current manufacturing processes means building factories that can cost upwards of $150 million. Lehrman, the Genzyme Transgenics CEO, said animal production systems should require lower capital outlays.

Not that the process is cheap, fast or easy -- yet. Scientists must first harvest the female animal's eggs, fertilize them in vitro and implant human genes into these embryos to produce the desired therapeutic protein.

These transgenic embryos must then be transplanted into surrogate mothers, who would give birth to the animals. Once they grow to adulthood, the animals that produce the highest concentration of drug in their milk are bred to create a herd.

Lehrman estimates it would require 30 to 100 goats to produce enough refined protein to supply a typical commercial drug program. It might take two or three years to create such a production herd.

Later this year, the FDA will hold a scientific meeting to consider the safety issues raised by transgenic animal production of human therapeutics. Drohan said one question is whether humans might develop allergic reactions to proteins produced in animals. So far, this hasn't been a problem, but regulators will take the issue seriously.

Another likely question is whether infectious agents in animals -- like mad cow disease -- might somehow jump to humans. Lehrman said the key thing to remember is that humans won't ingest the animal product directly. "We have a strong downstream pharmaceutical purification process," she said.

Given the number of transgenic animal products in human clinical trials, it seems likely some will ultimately pass FDA muster. But even should animals become approved as therapeutic protein factories, it's still way too early to judge whether transgenic milk will ultimately supplant the stainless steel vat or simply become a niche production method.

But the very prospect of using animals as drug factories is yet another example of how biotechnology is altering the very fabric of life.

Copyright ) 2000 Dow Jones Reuters Business Interactive LLC. All Rights Reserved

-- Bill P (porterwn@one.net), January 19, 2000

Answers

Bill P:

This work has been going on for some time The SFC has just arrived on the scene very late. They have been too interested in the latest scandels of the stars. It is also possible that such things will be produced in plants. My world and welcome to it!

Best wishes,,,

-- Z1X4Y7 (Z1X4Y7@aol.com), January 19, 2000.


So, a further way to exploit animals--use them as factories. Sorry to be anti-science, but--blech.

-- Mara (MaraWayne@aol.com), January 20, 2000.

We certainly are a species of twiddlers aren't we? We just keep twiddling and twiddling; and I'm sure you've noticed how _____ is always harmless in the beginning.

-- Will (righthere@home.now), January 20, 2000.

Hey, genetic engineering is going to produce abominations and monstrous crimes against Nature itself, of a type and scale we aren't able to even imagine yet. No GOd, no morality or law, will stop the progress of the new Mammon, Science.

At least we'll get cheaper drugs out of it. Might as well sit back and enjoy the show, eh?

-- Forrest Covington (theforrest@mindspring.com), January 20, 2000.


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