A novel class of cancer therapies called live biologics is offering new
hope for patients affected by hard-to-treat cancers, according to two
different studies testing the therapies in patients with sarcomas and
head and neck cancers.

Traditional cancer treatments such as chemotherapy and radiotherapy come
with a serious disadvantage: they cannot distinguish cancer cells from
normal cells. Since normal cells can be stunted by chemotherapy and
destroyed by radiation along with abnormal cells, patients may
experience serious health issues during a course of extended treatment.

Calgary-based Oncolytics Biotech Inc. has developed an innovative
approach to cancer therapy that might help patients avoid such serious
side effects. Their strategy relies on one of the human body’s
traditional foes: viruses. Specifically, Oncolytics is testing a live
cancer biologic called REOLYSIN®, which is derived from the human
reovirus.

“One of the distinguishing characteristics of the reovirus is its
tendency to replicate within certain cancer cells, namely, those that
possess a feature known as an activated Ras pathway,” said Brad
Thompson, Chairman, President and Chief Executive Officer of Oncolytics
Biotech. “Approximately two-thirds of all cancers involve cells that are
Ras-activated. REOLYSIN® appears to kill off these cancer cells by
rupturing their walls, creating a chain reaction of ‘explosions’ that
rip through tumors.”

A team lead by Dr. Monica Mita at the Institute of Drug Development (IDD),
the Cancer Therapy and Research Center at the University of Texas Health
Science Center (UTHSC) in San Antonio, Texas, recently provided updated
results from a Phase II study using REOLYSIN® in patients with sarcomas
metastatic to the lung.

The investigators reported that the treatment has been well-tolerated to
date, and that 19 of 44 patients experienced stable disease ranging from
2 to 20 months, resulting in a total clinical benefit rate (complete
response + partial response + stable disease) of 43%. The response
objective for the study was three or more patients having prolonged
stabilization of disease (>6 months) or better, for the agent to be
considered. The trial exceeded its established objective with six
patients experiencing stable disease for more than six months. Two
patients have experienced stable disease for more than 19 months. One of
these patients has synovial cell sarcoma that relapsed following
surgery, while the other has Ewing’s Sarcoma and had previously
progressed following multiple treatments.

“We were very happy to participate in the study,” said Dr. Mita.
“REOLYSIN® is a promising option for patients with sarcoma, as shown by
the results of this study. As a single agent, the virus had a clinical
benefit rate of 43% and it was very well-tolerated. We are contemplating
further studies combining REOLYSIN® with chemotherapy in order to
integrate the virus in the panoply of agents used for sarcoma
treatment.”

New Progress on Head and Neck Cancer

While the new viral treatment will not completely dispose of the need
for chemotherapy, its ability to weaken and shrink tumors might restrict
the amount of chemo that is required or help agents such as paclitaxel
and carboplatin do their jobs.

The company recently provided updated results from a Phase I/II UK trial
(REO 011) of REOLYSIN® combined with paclitaxel/carboplatin for patients
with advanced cancers in a poster presentation at the 2009
AACR-NCI-EORTC Molecular Targets and Cancer Therapeutics conference in
Boston. The investigators reported that REOLYSIN® was well-tolerated
when administered intravenously in combination with paclitaxel and
carboplatin. Of 19 evaluable patients with head and neck cancer, mostly
SCCHN refractory to prior platinum-based chemotherapy for
recurrent/metastatic disease, eight experienced partial responses and
six had stable disease. The total clinical benefit rate (complete
response + partial response + stable disease) observed in head and neck
cancer patients in the trial was 74%. Of four patients with malignant
melanoma on the trial, one experienced a partial response and one had
stable disease.

“A 42% response rate and a 74% clinical benefit rate in a platinum
refractory patient population that typically has a poor prognosis and
limited therapeutic options is very encouraging,” said Dr. Thompson.
“These results further validate our decision to advance REOLYSIN® in
combination with paclitaxel and carboplatin into a Phase III trial in
this patient population.”

For more information, log on to

www.oncolyticsbiotech.com