Cancer drugs:


REOLYSIN: A DRUG THAT KILLS
CANCER CELLS BY INFECTING THEM
Oncolytics Biotech, a Canadian
company,  is testing a reovirus (an
RNA virus often found in human lungs
but thought to be nonpathogenic)
against several types of cancer,
including that of the lung and skin as
well as head and neck malignancies.
The company says the reovirus
selectively infects cancer cells over
healthy ones because once a cell
turns malignant it stops making an
antiviral factor called protein kinase R.
The reovirus takes advantage of this
deficit to replicate inside cancer cells.
At London's Institute of Cancer
Research, UK, in Phase 1 trials, most
patients who had a range of advanced
cancers - including lung, bowel,
ovarian and skin cancer - that had
stopped responding to traditional
therapies, saw their tumors either
shrink or stop growing.
Reolysin is based on a virus called
Reovirus and is being used in studies
to treat and possibly cure ovarian
cancer. This virus vaccine is designed
to "turn off" the uncontrolled tumor cell
growth in the Ras Pathway.
The cells in our bodies have a natural
antiviral mechanism to fight off a virus.
When the Ras Pathway is turned on,
the antiviral activity is turned off. The
way the vaccine will work is that
because it is a virus, the patient will be
purposefully injected with it. When the
antiviral activity is turned off, as in
cancer cells, the virus will grow in
these cancer cells, divide, and kill the
cells in about three days. It does not
affect the healthy cells that can fight
off the virus on their own. As the
unhealthy cells die, it infects the
surrounding tissue.
This infection- kill cells- re-infection
cycle will go on usually for about two
weeks.

In stage I and II trials, the Reolysin
vaccine is being used in combination
with other anti-cancer drugs.
Drugs have side effects that actually
help the virus out. For example, some
chemo drugs change the blood
vessels and make them more
permeable for the virus to get into the
cell.
Currently, the trial participants go to
the Ohio State University Hospital as
outpatients to receive the vaccine
treatment. It is intravenous and takes
about 45 minutes to infuse. It is a daily
Monday-Friday cycle, then off for three
weeks, then Monday-Friday, then off
for three weeks. This is co-ordinated
with other drugs depending on the
drug's cycle. The patient needs some
recovery time due to side effects.
Stage III trials are to begin soon.

Reolysin is currently under
investigation in ten U.S. and U.K
clinical trials for a variety of cancers,
including tumors of the lung, head and
neck, bone or soft tissue, colon, skin,
and ovaries. In some trials, as in the
ovarian cancer trial, Reolysin is
administered alone; in others patients
receive it along with chemotherapy. So
far, reported results have been
extremely encouraging, with many
patients seeing their cancers stabilize
or shrink significantly.




ONCOVEX, THE ENGINEERED
HERPESVIRUS DRUG FOR
MELANOMA
Biovex with its engineered  herpesvirus
targeting advanced melanoma,  has
entered phase III clinical trials. Some
200 patients have received the virus
as part of the trial, and the company
expects to announce early results from
the test by the end of the year.
The group is also  launching a phase
III trial of the engineered virus, called
OncoVex, for head and neck cancer.
The herpesvirus delivers GM-CSF to
tumors, creating a localized immune
response.
GM-CSF is a substance that helps
make more white blood cells,
especially granulocytes, macrophages,
and cells that become platelets.
A similar virus, called H101, is already
marketed in China to treat head and
neck cancers.
BioVex believes OncoVEXGM-CSF has
the potential to become a leading
standard of care in the treatment of
many solid tumors based on the
strength of clinical data so far
generated coupled with the relatively
benign side effect profile  to date.



JENNEREX: VACCINIA VIRUSES  
MULTIPLY THEMSELVES IN CANCER
CELLS
Jennerex products are the first in a
novel, revolutionary, breakthrough
product class of cancer therapeutics -
vaccinia viruses that have been
engineered to target, attack and
eradicate cancer without harming the
surrounding cells.
Unlike "vectors" or "vaccines",
Jennerex products multiply themselves
in cancer cells, leading to cancer cell
destruction, while normal cells are left
unharmed. Their products are
activated  by genetic pathways that are
critical to the vast majority of human
cancers, including common solid
tumors such as lung, colon, prostate,
breast, pancreas and melanoma. They
employ a novel primary mechanism-of-
action that is effective even against
cancers that are resistant to standard
therapies such as chemotherapy, small
molecule tyrosine kinase inhibitors,
antibodies and radiotherapy.
The vaccinia virus showed
effectiveness against liver cancer in a
phase II clinical trial and will move into
a phase III trial later this year,


OTHER DEVELOPMENTS
ERBITUX
Eli Lilly & Co. and Merck KGaA’s
Erbitux, approved for advanced colon
cancer, failed to slow tumors in a study
designed to expand the medicine’s use
to patients whose disease is in an
earlier stage.
Erbitux, used to treat aggressive
colorectal tumors that have reached
other areas of the body, didn’t help
stop the spread when added to
chemotherapy, according to a study
reported today at the American Society
of Clinical Oncology meeting in
Chicago. Erbitux added to the side
effects of chemotherapy.
The finding is the latest of at least
three studies that have narrowed the
scope of a drug that was the first of its
kind for colon cancer when approved
in 2004. Last year, Erbitux’s
prescribing information was changed
to say that patients whose tumors have
a mutation to a gene called KRAS --
found in about 40 percent of colon
cancer cases -- aren’t helped by the
treatment.