By Ben Hirschler and Kate Kelland
LONDON | Tue Nov 16, 2010 11:52am EST

LONDON (Reuters) - Doctors in Scotland working with British biotech
company ReNeuron have injected stem cells into the brain of a man in a
pioneering clinical trial to test the safety of a therapy for patients
disabled by stroke.

The trial is the first in the world to use neural stem cell therapy in
stroke patients, its organisers said on Tuesday, and external experts
said it was grounds for "cautious optimism."

Keith Muir of the University of Glasgow's Institute of Neuroscience
and Psychology, the principal investigator, said the surgery on the
first patient, a man in his 60s, had gone well and he had been
discharged from hospital.

"He will be monitored closely for two years, as will all the patients
in the trial," said a spokeswoman for the university.

The procedure involves injecting ReNeuron's neural stem cells into
patients' brains in the hope they will repair areas damaged by stroke,
thereby improving both mental and physical function. This first trial
is designed primarily to test whether the experimental treatment is
safe for stroke patients.

"We hope that in future it will lead on to larger studies to determine
the effects of stem cells on the disabilities that result from
stroke," Muir said in a statement.

The nature of the procedure and the characteristics of the cells mean
that patients do not need to take immunosuppressant drugs after
receiving treatment, the research team said.

Unlike U.S. company Geron's clinical trial in patients with spinal
cord injuries, which started last month, the Scottish study uses stem
cells derived from human fetuses rather than embryos.

Foetal stem cells do not have the same flexibility to turn into
different tissue types as embryonic ones.

Shares in ReNeuron, which won regulatory approval for the trial in
January and had initially hoped to launch it in the second quarter of
2010, rose more than 18 percent on the news, before settling back to
trade 16 percent higher by 8:20 a.m. EST.

Scientists commenting on news of the trial said it was important to
guard against raising expectations of miracle cures for thousands of
patients in the near future.

"The current trial will require extensive tests for efficacy and
safety," said Darren Griffin, a professor of genetics at Britain's
Kent University, who is not involved in the study. "Nevertheless,
there is room for cautious optimism."

In total, 12 patients will get ReNeuron's ReN001 cell therapy between
six and 24 months after having an ischaemic stroke -- caused by a
blockage of blood flow in the brain -- and their progress will be
followed for two years in the trial.

If the first study is successful, researchers plan to pursue
accelerated clinical development in later-stage clinical trials,
focusing initially on more severely disabled stroke patients.

Stem-cell technology is viewed as a highly promising new area of
medical science, but it has proved controversial, in part because some
cell lines are derived from embryos or fetuses. Other research teams
are also working with adult stem cells.

Full story
http://www.reuters.com/article/idUSTRE6AF1SM20101116