 |
|
|
A new study by UK scientists
reveals that a genetically created herpes-based virus is an effective remedy
against skin cancer.
This virotherapy raises life expectancy for patients with aggressive melanoma
and has fewer side effects than other treatments.
The
worldwide study, which was led by the Institute of Cancer Research in the UK
and published in the Journal of Clinical Oncology, says that an artificially
created virus called T-VEC can provide skin cancer patients with more
efficacious treatment.
RT.com/Reuters report:
Clinical
trials have been going on for more than three years in 64 centres across the
US, UK, Canada and South Africa. If further studies are also successful, the
new drug will be more widely available by next year, the scientists predict
according to the Guardian.
T-VEC
is a modified herpes virus which multiplies inside cancer cells until they
burst open. After destroying the cancer cell, the virus gets into surrounding
area and triggers a secondary immune reaction against the tumour.
Dr
Hayley Frend, science information manager at Cancer Research UK, commented: “Using
a virus to both kill cancer cells and nudge the immune system into attacking
them is exciting. Previous studies have shown T-VEC could benefit some people
with advanced skin cancer, but this is the first study to prove an increase in
survival.”
The
virus is deprived of two key genes, which makes it impossible for it to
replicate in healthy cells – so, normal cells detect and destroy T-VEC before
it can cause damage. That means the virus is practically safe for patients.
During
the research more than 400 patients were injected with the drug every two weeks
for up to 18 months. They had flu-like symptoms after the first few injections,
but on the whole such treatment has much milder side effects than other
therapies.
The
scientists appreciate the results of the study as highly positive. Patients
with stage three and early stage four melanoma lived on average for 41 months
after T-VEC-therapy, while other people with the same stage of skin cancer
lived for only 21.5 months. Ten percent of the patients had “complete
remission” with no detectable symptoms of cancer – regarded as a cure if the
patient is still cancer-free between three and five years after diagnosis.
“This
is the big promise of this treatment. It’s the first time a virotherapy has
been shown to be successful in a phase 3 trial,” Kevin Harrington, professor of
biological cancer therapies at the Institute of Cancer Research London said, as
cited by the Guardian.
“The
results are especially encouraging, because all the patients had inoperable,
relapsed or metastatic melanoma with no conventional treatment options
available to them. They had disease that ranged from dozens to hundreds of deposits
of melanoma on a limb all the way to patients where cancer had spread to the
lungs and liver,” he added.
The
scientists noticed one more interesting feature – the immune system after the
T-VEC therapy becomes capable of detecting and attacking cancer throughout the
body. As a result, even secondary tumours not infected also shrank or even
disappeared. “It’s like an unmasking of the cancer,” explained Mr Harrington. “The
patient’s immune system wakes up and attacks the cancer cells wherever they are
in the body.”
If
the success of virotherapy as a remedy against skin cancer is proved, it will
give hope that the same methods will be effective in the treatment of other
types of cancer.
The
idea of curing cancer with viruses isn’t new – it emerged in the early 20th
century. In 1949, 21 patients with Hodgkin’s lymphoma were injected with viral
hepatitis. Seven people had temporary remission while one died and 13 others
contracted hepatitis. Today, virotherapy is much safer due to genetic
engineering, which allows for creating less dangerous versions of natural
viruses.
“We
may normally think of viruses as the enemies of mankind, but it’s their very
ability to specifically infect and kill human cells that can make them such
promising cancer treatments,” the Telegraph quoted Professor Paul Workman, CEO
of the Institute of Cancer Research, London.
According to the “World
Cancer Report 2014” published by the World Health Organization, 232,000 people
across the world had skin cancer and 55,000 died of it in 2012. About 88
percent of patients live for more than five years after the detection of the
disease, but life expectancy for aggressive forms of skin cancer with the
illness spreading to other organs is much lower.
No comments:
Post a Comment