A Cancer vaccine that can train cancer patients’ own bodies to seek out and destroy tumour cells has been developed by scientists.
By
Richard Gray, Science Correspondent
8:00AM BST 08 Apr 2012
The therapy, which targets a molecule found in 90 per cent of all
cancers, could provide a universal injection that allows patients’
immune systems to fight off common cancers including breast and prostate
cancer.
Preliminary results from early clinical trials have shown the vaccine
can trigger an immune response in patients and reduce levels of disease.
The scientists behind the vaccine now hope to conduct larger trials
in patients to prove it can be effective against a range of different
cancers.
They believe it could be used to combat small tumours if they are
detected early enough or to help prevent the return and spread of
disease in patients who have undergone other forms of treatment such as
surgery.
Cancer cells usually evade patient’s immune systems because they are
not recognised as being a threat. While the immune system usually
attacks foreign cells such as bacteria, tumours are formed of the
patient’s own cells that have malfunctioned.
Scientists have, however, found that a molecule called MUC1, which is
found in high amounts on the surface of cancer cells, can be used to
help the immune system detect tumours.
The new vaccine, developed by drug company Vaxil Biotheraputics along
with researchers at Tel Aviv University, uses a small section of the
molecule to prime the immune system so that it can identify and destroy
cancer cells.
A statement from Vaxil Biotheraputics said: “ImMucin generated a
robust and specific immune response in all patients which was observed
after only 2-4 doses of the vaccine out of a maximum of 12 doses.
“In some of the patients, preliminary signs of clinical efficacy were
observed.”
The results are still to be formally published but if further trials
prove to be successful the vaccine could be available within six years.
As a therapeutic vaccine it is designed to be given to patients who
are already suffering from cancer to help their bodies fight off the
disease rather than to prevent disease in the first place.
Cancer cells contain high levels of MUC1 as it is thought to be
involved helping tumours grow. Healthy human cells also contain MUC1,
but have levels that are too low to trigger the immune system after
vaccination.
When a vaccinated patient’s immune system encounters cancer cells,
however, the far larger concentration of MUC1 causes it to attack and
kill the tumour.
As MUC1 is found in 90 per cent of all cancers, the researchers
believe it could be used to combat the growth and spread of a wide range
of cancers.
In a safety trial at the Hadassah Medical Centre in Jerusalem, ten
patients suffering from multiple myeloma, a form of blood cancer, have
now received the vaccine.
Seven of the patients have now finished the treatment and Vaxil
reported that all of them had greater immunity against cancer cells
compared to before they were given the vaccine.
Vaxil added that three patients are now free of detectable cancer
following the treatment.
The findings support research published in the journal
Vaccine, which showed the treatment induced “potent” immunity
in mice and increased their survival from cancer.
Cancer charities have given the vaccine a cautious welcome, but
warned further testing was needed before it could be approved for
widespread use.
There are currently a number of other therapeutic vaccines against
cancer being tested, but they have met with limited success.
Dr Kat Arney, science information manager at Cancer Research UK,
said: “There are several groups around the world investigating
treatments that target MUC1, as it’s a very interesting target involved
in several types of cancer.
“These are very early results that are yet to be fully published, so
there’s a lot more work to be done to prove that this particular vaccine
is safe and effective in cancer patients.”
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