VANCOUVER, Oct. 8 /CNW/ - Protox Therapeutics Inc. (TSX: PRX), a leader
in the development of receptor targeted fusion proteins, today announced
positive 12 month data from its Phase 1 study of PRX302 in patients with
benign prostatic hyperplasia (BPH), a common and bothersome urological
condition among the aging male population. The trial results indicate that
PRX302 continues to show very promising signs of therapeutic activity at
12 months following a single treatment of PRX302.
"The impact of PRX302 on the quality of life of most patients has
continued to be dramatic," commented Dr. Peter Pommerville, co-principal
investigator at Can-Med Clinical Research Centre in Victoria, B.C. "Unlike
other minimally invasive techniques, the most impressive feature of PRX302
treatment is the sustainability of symptom improvement and a low side effect
"We are very pleased with the twelve month data and the positive response
from our clinical investigators," said Dr. Fahar Merchant, President and Chief
Executive Officer of Protox. "The extended duration of improvement in symptom
scores following a single treatment are compelling especially when a reduction
in IPSS by greater than four points is deemed to be highly clinically
This study was an open-label, multi-centre, dose escalation study where
the primary endpoint was safety and tolerability following a single
intra-prostatic administration of PRX302. The secondary endpoint was to
determine therapeutic activity as measured by the change in International
Prostate Symptom Score (IPSS) following treatment, when compared to screening.
In addition, changes in Quality of Life (QoL) scores and prostate volume were
also monitored. A total of 15 patients with moderate to severe BPH were
treated in this trial. Most patients treated in this study were either
refractory or intolerant to oral therapy.
Therapeutic activity of PRX302 was evaluated at 12 months post-treatment
using standardized symptom indices, namely, IPSS and QoL. IPSS assesses the
severity of seven key symptoms of BPH, (incomplete emptying, frequency,
intermittency, urgency, weak stream, straining and nocturia). The QoL score is
measured on a scale from 0-6 with 0 defined as "delighted" and 6 defined as
"terrible" with respect to patient quality of life due to BPH.
As reported earlier this year, treatment related symptomatic relief was
rapid and substantial benefits were noticed by day-30 post-treatment without
any safety issues. Both symptom scores (IPSS and QoL) continued to show
further improvements in all cohorts at the end of the active study period
(day-90 post-treatment) indicating a potential for sustained benefit following
a single treatment with PRX302.
Following the active study period, 14 of 15 patients continued to be
followed at 12 months post-treatment and the IPSS scores continue to show a
statistically significant improvement from screening (p (less than) 0.01). The
mean IPSS values improved by an average of 6.5 points from 19.2 +/- 4.5 at
screening to 12.7 +/- 4.6 at 12 months post treatment. The improvements were
observed across all seven symptom sub-scores.
Improvement in QoL scores were observed in all five cohorts. Independent
of the treatment group, QoL scores continue to show a statistically
significant improvement from an average of 4.6 +/- 1.0 at screening to 2.6 +/-
1.6 at 12 months (p (less than) 0.01), a 44% improvement. Furthermore,
prostate volume decreased in all cohorts. Irrespective of cohort assignment,
the mean prostate volume decreased by over 13% from 43.6 cc at screening to
38.1 cc at 12 month post-treatment.
As announced previously, enrollment of Protox's Phase 2a study evaluating
PRX302 for the treatment of BPH has been completed. Top-line data from this
study will be released in the fourth quarter of 2008.
BPH is a common urological condition characterized by painful and
bothersome symptoms that include difficulty in initiating a urine stream, a
sense of urgency, leaking, dribbling and presence of blood in the urine. The
condition affects over 50 million men throughout North America, Europe and
Japan. More than half of all men will have symptoms of BPH by age 60 and as
many as 90% may suffer from BPH after the age of 70. Left untreated, it can
result in serious and possibly irreversible bladder damage. Current drug
therapies only provide symptomatic relief and may trigger a range of side
effects including impotence and hypotension. Surgical options such as TURP
(transurethral resection of the prostate), which constitute the second-largest
item in the US Medicare budget, can cause impotence, incontinence as well as
other more serious procedure-related effects. According to Wood Mackenzie
(2007), the market opportunity for therapies used to treat BPH was
US $5.5 billion in drug therapies and US $4 billion in surgical procedures.
PRX302 is the lead drug in the company's PORxin(TM) technology platform.
PORxin drugs are pore-forming pro-drugs that are activated by specific
proteases produced at elevated levels on the surface of target cells. PRX302
has been generated by engineering the naturally occurring toxin proaerolysin
so that it is activated by prostate-specific antigen (PSA), an enzyme that is
overproduced in patients suffering from prostate cancer and BPH (benign
prostatic hyperplasia or enlarged prostate). Once activated, the drug punches
holes in the cells causing the contents to leak out and ultimately cell death.
Protox Therapeutics is a leader in advancing novel, receptor targeted
fusion proteins. 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 and EMEA. Phase
2a clinical trials evaluating PRX302 (PORxin) for the treatment of localized
prostate cancer and benign prostatic hyperplasia (enlarged prostate) are
ongoing. Protox is also collaborating with the U.S. National Institutes of
Health (NIH) on a research program focused on the discovery of next generation
fully human targeted therapeutics.
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.
For further information:
For further information: James Beesley, Senior Director, Investor
Relations, Protox Therapeutics, (604) 484-0975,
firstname.lastname@example.org; Michael Moore, Investor Relations, Equicom
Group, (416) 815-0700 x 241, email@example.com