FEATURE-Brain repair companies sharpen their drills
 By Ben Hirschler, European pharmaceuticals correspondent

http://biz.yahoo.com/rf/001105/l31349052.html

LONDON, Nov 6, 2000 (Reuters) - A local anaesthetic, a small drill-hole
in the skull and a syringe full of new cells may one day be all it takes
to cure brain damage.

That, at least, is the hope of scientists pioneering a new kind of
``brain repair kit" using implants of mass-produced cells to patch up
damaged grey matter.

The daring approach offers hope to those incapacitated by stroke or
degenerative diseases such as Alzheimer's or Parkinson's. However,
experts say it will take years before it is proved to be safe and
effective.

A growing number of companies are lining up to commercialise the
technology, including Britain's ReNeuron -- a spin-off from the
Institute of Psychiatry -- which plans to raise 15-20 million pounds
($22-29 million) with its initial public offering on London's
Alternative Investment Market this week.

ReNeuron uses neural stem cells, grown in culture from aborted foetus
tissue, to regenerate damaged parts of the brain. Stem cells are
immature ``master'' cells which can be coaxed into forming virtually any
type of tissue in the body.

It has proved the principle in rats and plans to start trials on humans
in the second half of next year.

ReNeuron is not alone. At least five other companies are operating in
the field with the most advanced work to date done in the United States.

The idea of transplanting cells into damaged brains is not altogether
new.

For the last 10 years, doctors have been treating a handful of
Parkinson's disease patients using cells transplanted from the brains of
aborted foetuses. The technique, pioneered by scientists at Sweden's
Lund University, has been shown to alleviate the worst symptoms of the
disease.

But it takes an average of six foetuses to treat an adult brain, making
the process practically -- and ethically -- problematic.

Biotechnology companies believe they have now found ways round this
supply problem.

One option, being pursued by ReNeuron and several others, is to use
genetic engineering to ``immortalise'' human cell lines which can then
be produced indefinitely in the laboratory.

Another approach is to turn to animal tissue.

The U.S. company Diacrin Inc, which is further advanced than its rivals
in terms of clinical trials, harvests brain cells from the foetuses of
pigs for implant into humans.

Its research suffered a setback earlier this year after two two cases of
complications in stroke patients. But product development is continuing
and Diacrin is also investigating using porcine cells to treat spinal
cord injury and to repair damaged heart muscle.

Nevertheless, many medics have reservations about animal-to-human
transplants -- with some speculating they might spread as yet unknown
viruses -- and other firms in the field are concentrating on human
tissue.

They include the privately owned U.S. company Layton BioScience which
reported two months ago that it had successfully treated stroke patients
using human cancer cells that had been ``retrained'' to become nerve
cells.

Among others in the field are U.S. companies StemCells Inc
(NasdaqNM:STEM - news) and unlisted NeuralStem Biopharmaceuticals Ltd,
together with the private British firm CellFactors.

The two U.S. firms, like ReNeuron, are working with stem cells while
CellFactors is studying the mass-production of specific brain cell
types.

Doctors have recently been intrigued by growing evidence of of the
brain's ability to repair itself, as demonstrated, for example, by
dramatic recoveries in some infant stroke victims.

Cell implants might eventually make that kind of a recovery routine for
adults.

But Owen Redahan, director of Britain's Stroke Association, says there
is still a great deal to prove.

"The principle is interesting but it's going to be extremely complicated
to get the cells to take over functions that have been destroyed after a
stroke,'' he said.

"I think it will take up to 10 years before we can say whether or not it
is really possible."

Research so far suggests that cells -- whether human or porcine -- can
be transplanted successfully to replace damaged ones. But the big
question is whether the brain functions that died when the original
brain cells died are replicated precisely, Redahan said.

Martin Edwards, chief executive of ReNeuron, admits it will be a long
haul.

"I don't think a product like ours will be on the market for about eight
years because the clinical trials required are likely to be long and
quite difficult, although some of our competitors are far more bullish
and talk of something by 2004 or 2005,'' he said.

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Judith Richards, London, Ontario, Canada
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