LONDON Three of Europe's top drugmakers have
backed a new public-private scheme to use stem cells for safety
testing of experimental medicines, signaling "big pharma's"
growing interest in the controversial field.
Stem Cells for Safer Medicines Ltd, a non-profit British
company launched on Wednesday, will focus initially on
developing better ways of testing for liver toxicity -- the
biggest single cause of drug failures and withdrawals.
GlaxoSmithKline, AstraZeneca and Roche have each paid
100,000 pounds ($200,000) to help fund the first year's work,
while the British government is contributing 750,000 pounds.
Other drug firms are expected to join soon, according
Philip Wright, director of science and technology at the
Association of the British Pharmaceutical Industry, the firm's
Stem cells are the body's master cell, acting as a source
for the body's cells and tissues. Embryonic stem cells are the
most malleable, but their use in research is opposed by some
people because it involves destruction of a human embryo.
Britain, however, has encouraged such research and science
minister Ian Pearson said the new collaboration was an example
of the government's commitment to the field.
By working across academic and industrial laboratories, the
project aims to develop effective ways of using human embryonic
stem cells to screen for potentially dangerous side effects of
new drugs before they go into clinical trials.
It will not evaluate stem cells as potential treatments.
Ian Cotgreave, head of molecular toxicology at AstraZeneca,
said there were still significant hurdles to overcome in
differentiating liver cells from existing stem cell lines but
the technology could dramatically improve R&D productivity.
"The big problem is that, not knowing any better, we are
today putting compounds into the regulatory (approval) system
that then fall down in the clinic," he told reporters.
More than 90 percent of drugs entering clinical development
fail to get to market, due to lack of effectiveness or adverse
side effects that were not picked up in animal tests.
The liver is particularly vulnerable, since it acts as the
body's garbage removal system. High-profile drug failures due
to liver problems include AstraZeneca's anti-thrombotic Exanta
and Pfizer's diabetes drug Rezulin.
The next research area will be heart cells, where new tests
could shed light on cardiovascular side effects like those that
led to the withdrawal of Merck & Co's Vioxx in 2004.