Cloning could create life-saving drugs faster-PPL
10:14 a.m. Sep 08, 1998 Eastern

By Mike Peacock

CARDIFF, Sept 8 (Reuters) - The company that produced Dolly the sheep, the world's first cloned mammal, said on Tuesday that cloned livestock could be used to produce large amounts of lifesaving drugs much faster and cheaper in future.

British biotechnology firm PPL Therapeutics said it is developing technology, using transgenic livestock, to create ``virtually unlimited'' quantities of human proteins for therapeutic use.

``We can make very large amounts of the protein using this process and we can make it very cheaply,'' Dr Ian Garner of PPL, told a news conference at the annual British Association festival of science in Cardiff.

The process involves adding a small piece of DNA to the DNA of a sheep, cow or rabbit, allowing it to make one extra protein -- a human one.

``The human protein is secreted into the milk of a lactating female so that it is very easy to access the raw material from which to purify the desired product,'' Barker said. ``If more product is required you simply breed more sheep, cows or rabbits.''

Last month, PPL announced the birth, at its farm in Scotland, of transgenic lambs that carry a human protein that could eventually be used in organ transplants and heart surgery.

Up to now, human proteins for therapeutic use have generally been taken from human blood. That carries a risk that viruses or prions are not removed, threatening patients who take those products with AIDS, hepatitis or Creutzfeldt-Jakob Disease (CJD), the human form of mad cow disease.

Garner said recent advances have allowed the production of some proteins in large vats of animal cells -- a process similar to brewing. But that is expensive, unlike the generation of human proteins in transgenic livestock.

He said PPL's process was also much quicker.

``Manipulation of the cells in the laboratory means that you can dramatically shorten the time taken to push the product to the clinic where it will save patients' lives,'' Garner said, adding that the revolutionary process could lead to a 50 percent saving in time.

Barker said one example of the process in action was the development of alpha-1-antitrypsin (AAT), seen as a potential cure for cystic fibrosis which affects around 55,000 people every year in the United States and Europe.

Garner said initial trials suggested the product was safe but longer, six-month tests were now underway.

``If the trend continues...the prospects will be much brighter than we first thought,'' he said. ``We will be able to treat patients perhaps three to four years earlier than before.''

The next major step will be the creation of an animal that has a single gene removed or replaced with the human equivalent, Garner said, something PPL has received a government grant to help develop. ``That is what we are trying to do now.''

Then it will even be possible to produce a cow which is unable to make the prion proteins that experts believe are linked to BSE, or mad cow disease. ``It would make them resistant to BSE although it is not something PPL would get involved in,'' Barker said.

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