Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: THURSDAY, August 31, 1995 TAG: 9508310076
SECTION: NATIONAL/INTERNATIONAL PAGE: A-14 EDITION: METRO
SOURCE: LAURAN NEERGAARD ASSOCIATED PRESS
DATELINE: WASHINGTON LENGTH: Medium
It sounds like science fiction: milking enough medicine out of 10 genetically engineered goats to replace an entire pharmaceutical factory.
But some researchers consider ``milked medicines'' the future in affordable drugs, and last week the Food and Drug Administration quietly signaled it is ready to do business with these ``biopharmers.''
The FDA issued the nation's first guidelines for medicines milked from animals whose genetic makeup has been altered by scientists, ``what we see as one of the next major technological boosts for biotechnology and the pharmaceutical industries,'' said Dr. Philip Noguchi, FDA's biotechnology chief.
The guidelines are ``a turning point'' that indicate companies should forge ahead with these drugs, said James Geraghty, president of Genzyme Transgenics Corp. He plans to test the first such drug on Americans next year.
At issue are proteins used to fight disease. They range from the Factor VIII that stops hemophiliacs' uncontrolled bleeding to TPA, which breaks blood clots during heart attacks but is so scarce that it costs $2,000 a dose.
Such medicines are culled from human blood or painstakingly grown in laboratory cell cultures that can produce a mere 100 milligrams of the drugs a day.
Animals genetically engineered to grow these proteins in their milk, usually goats, can produce at least 10 times that amount. Simply milk the animal, extract the protein from the milk and purify it.
And it is 10 times less expensive to genetically alter enough animals to produce the same amount of drug than it is to build a $50 million laboratory, Geraghty said.
But drug companies were reluctant to aggressively pursue this fledgling industry for fear of how strictly the FDA would regulate it.
``The technology is clearly available,'' said Dr. Richard Bowen of Colorado State University, who created the world's first transgenic calf. ``There's been a cloud hanging over that whole issue about regulatory affairs.''
That changed last week. The new guidelines are ``a signal that, yes, FDA has considered this and thinks that it's a reasonable way to go,'' Noguchi said.
Under the guidelines, companies seeking FDA approval for a milked medicine must detail how the animal was genetically altered and prove it has no disease or was given no medication that could taint its proteins. Also, the animal and its descendants must consistently produce protein of the same amount and quality, and the company must prove it can adequately purify the medicine.
Only after meeting those requirements can companies test the drugs in people to ensure they work as well as ones now available.
Genzyme Transgenics plans to start the first such tests next year, using the blood thinner antithrombin-III that it grows in goat milk. The scarce protein now is culled from human blood donations.
Up to 15 other U.S. companies are researching milked medicines. A Scottish firm may have the biggest producer, extracting 30 grams per liter of sheep's milk of alpha-1 antitrypsin, which fights emphysema.
``Obviously it can seem funny to people, like we're going backwards from stainless steel to a farm,'' Geraghty said. ``People are now realizing this is a more natural and more effective system.''
For some reason, it is easiest to genetically alter goats and sheep; Bowen is trying for similar success with cows, because they produce more milk.
The FDA won't say how soon one of these medicines could hit the market. ``But the amount of activity in this area will increase fairly significantly over the next several years,'' Noguchi predicted.
by CNB