Tests
begin for cancer virus
The following article
was taken from the Daily Telegraph Newspaper.
British doctors are
about to start start clinical trials of a new genetically modified virus that
destroys cancers without the unpleasant side-effects of chemotherapy and radiotherapy.
The GM virus, which
has been developed by cancer charities, hunts down a mutation found in 95 per
cent of tumour cells but ignores healthy cells. Once inside, it hijacks the
cell's machinery to replicate itself, destroys the cell and then spreads around
the body.
The virus, which has
so far only been tested on animals, is thought to be far more effective than
previous attempts at gene therapy. Doctors behind the pioneering treatment believe
it could one day be used against a range of tumours, including cancers of the
breast, pancreas and lung.
Initial
safety trials are being carried out at Hammersmith Hospital, London, on 30 seriously
ill patients for whom other treatments have failed. The tests are still at an
early stage and doctors are keen not to raise expectations. During the initial
"phase one" trials, they will attempt to establish a safe dose of
the virus.
Dr David Kirn, head
of the viral and genetic therapy programme at the Imperial Cancer Research Fund,
Hammersmith Hospital, describes the new approach in the journal Lancet Oncology.
GM viruses have been
used to target solid tumours in animal models for some years. But applying the
same approach to people has proved difficult. The process of engineering a virus
to specifically target cancer cells usually weakens the virus's ability to kill
tumours. But
for some unknown reason, the new virus replicates far more effectively than
earlier versions.
The first tests on people
with liver cancer should begin around Easter. The sudden arrival of a virus
can also prime the immune system and trigger a response against cancerous cells,
making the treatment even more effective. "Viruses have evolved over millions
of years to express many of the qualities required for the ideal anti-cancer
weapon," said DR Kirn.
"Viruses will target
and infect very specific types of cell, multiply, cause cell death and release
more viral particles to go on and infect other target cells."