Protox Announces Positive Final Data from Prostate Cancer Study
VANCOUVER, Nov. 1 /CNW/ - Protox Therapeutics Inc. (TSX-V:PRX)
today announced positive final results from its Phase 1 clinical
trial evaluating PRX302 in patients with localized, recurrent
prostate cancer following radiation failure. The trial results, an
extension of those released on July 10, 2007, indicate that PRX302
is well tolerated and shows promising signs of therapeutic
activity.
"In addition to demonstrating that PRX302 was well tolerated, early
signs of therapeutic activity seen at this stage are promising,"
said Dr. Scott Coffield, Principal Investigator from the lead site,
Scott and White Memorial Hospital. "These observations are
encouraging and are suggestive of the potential clinical benefit of
PRX302, particularly in light of the recurrent cancer seen in those
patients who had progressive disease following radiation
therapy."
This study was intended to examine the safety and tolerability of
PRX302 as a primary endpoint and therapeutic activity as a
secondary endpoint in patients with biopsy proven localized
recurrent prostate cancer following radiation therapy who showed
signs of disease progression as evidenced by rising levels of PSA
(prostate specific antigen). A total of 24 patients were treated in
this trial. The average age of patients in the study was 69.6
(range: 58-86).
Protox concluded that despite a 100-fold escalation in dose, the
maximum tolerated dose (MTD) was not reached in this study while
evidence of therapeutic activity was observed. As reported in July,
no significant safety issues were encountered in this clinical
trial. No serious adverse events were reported relating to PRX302
and most adverse events reported were associated with the injection
procedure, rating no higher than Grade 1 (mild). Assessment of
potential therapeutic activity was determined by prostate biopsies
at day-30 post-treatment and by measuring serial PSA
levels.
A comparison of prostate biopsies taken at baseline and day-30
post-treatment showed that 18 of the 24 patients tested in this
trial had a decrease in the percentage of cancer-positive biopsies.
Three of the patients showed no detectable cancer in their day-30
biopsy. Results showed that in 21 of the 24 patients a decrease in
PSA levels below screening levels were observed at 30 days or
longer post-treatment while in 15 of 24 patients PSA levels
continued to be below screening levels or stable at 90 days or
longer. Comparison of PSA levels pre- and post-treatment showed a
desirable trend towards an increase in PSA doubling time (PSADT) in
19 of 24 patients and a decrease or stable PSA velocity (PSAV) in
17 of 24 patients, both of which are positive outcomes for the
patient.
"We are very pleased that the results from this Phase 1 study of
PRX302 demonstrate its potential as a treatment for localized
prostate cancer," said Dr. Samuel Denmeade, Chief Scientific
Officer of Protox and co-inventor of PRX302. "These data, taken
together with the encouraging interim data on our Phase 1 BPH
study, further substantiate the promise of PRX302."
The company anticipates that a Phase 2a study evaluating PRX302 for
the treatment of patients with locally recurrent prostate
cancer following primary radiation therapy will commence before the
end of the year. The objective of this study is to amplify the
anti-cancer activity of PRX302 by using various intra-prostatic
injection regimens. The assessment of therapeutic activity will be
based on changes in PSA levels, PSAV, PSADT and tumor burden
(prostate biopsies) following treatment. The study will also
evaluate the safety and tolerability of the different regimens of
injection.
Conference call
Protox will host a conference call and live webcast today at
11:00 a.m. E.T. to discuss these results. To access the conference
call by telephone, dial 416-644-3420 or 1-800-733-7571. Please
connect approximately ten minutes prior to the beginning of the
call to ensure participation. The conference call will be archived
for replay until November 8, 2007 at midnight. To access the
archived conference call, dial 416-640-1917 or 1-877-289-8525 and
enter the reservation number 21252499 followed by the number
sign.
A live audio webcast of the conference call will be available at
www.protoxtherapeutics.com.
Please connect at least ten minutes prior to the conference call to
ensure adequate time for any software download that may be required
to join the webcast. The webcast will be archived at the above
website for 30 days.
About Prostate Cancer
Prostate cancer is a leading cause of cancer death in North American men. One in every six men is diagnosed with prostate cancer during their lifetime. The American Cancer Society estimates that during 2007 approximately 219,000 new cases of prostate cancer will be diagnosed and over 27,000 men will die from the disease in the U.S. Current treatment options for localized prostate cancer include surgery and radiation therapy. Serious side effects are associated with these therapies including erectile dysfunction, incontinence, urinary dysfunction and bowel problems.
About Protox
Protox Therapeutics is a leader in advancing novel, targeted protein toxin therapeutics for the treatment of cancer and other proliferative diseases. Two novel drug candidates derived from the company's INxin(TM) and PORxin(TM) platforms are being developed in three clinical programs. A Phase 2a clinical trial evaluating PRX321 (INxin) for the treatment of primary brain cancer has been completed and the drug has received Fast Track Designation and Orphan Drug Status from the US FDA. Phase 1 clinical trials evaluating PRX302 (PORxin) have been completed for the treatment of localized prostate cancer and benign prostatic hyperplasia (enlarged prostate).
NO REGULATORY AUTHORITY HAS APPROVED OR DISAPPROVED THE CONTENT OF THIS RELEASE. THE TSX VENTURE EXCHANGE DOES NOT ACCEPT RESPONSIBILITY FOR THE ADEQUACY OR ACCURACY OF THIS RELEASE.
Certain statements included in this press release may be
considered forward-looking. Such statements involve known and
unknown risks, uncertainties and other factors that may cause
actual results, performance or achievements to be materially
different from those implied by such statements, and therefore
these statements should not be read as guarantees of future
performance or results. All forward-looking statements are based on
Protox' current beliefs as well as assumptions made by and
information currently
available to Protox and relate to, among other things, anticipated
financial performance, business prospects, strategies, regulatory
developments, market acceptance and future commitments. Readers are
cautioned not to place undue reliance on these forward-looking
statements, which speak only as of the date of this press release.
Due to risks and uncertainties, including the risks and
uncertainties identified by Protox in its public securities
filings; actual events may differ materially from current
expectations. Protox disclaims any intention or obligation to
update or revise any forward-looking statements, whether as a
result of new information, future events or otherwise.
-30-
/For further information: James Beesley, Director, Investor
Relations,
Protox Therapeutics, (604) 688-0199, jbeesley@protoxtherapeutics.com;
Michael
Moore, Investor Relations, Equicom Group, (416) 815-0700 x
241,
mmoore@equicomgroup.com/
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