Protox Therapeutics Inc. (TSX: PRX), a leader
in the development of receptor targeted fusion proteins, today announced
positive results from its Phase 1 study evaluating PRX302 in patients with
benign prostatic hyperplasia (BPH), a common and bothersome urological
condition among the aging male population. The results indicate that promising
signs of therapeutic activity continue to be seen at 6-months and 9-months
following a single treatment with PRX302.
    "Patients treated with PRX302 continue to show a good response to
treatment with stabilization of symptoms and maintenance of voiding pattern,"
commented Dr. Peter Pommerville, co-principal investigator at Can-Med Clinical
Research Centre in Victoria, B.C. "The fact that symptom improvement has been
maintained to 9 months indicates the lasting effect of PRX302 on prostate
    Therapeutic activity of PRX302 was assessed using standardized symptom
indices, namely, International Prostate Symptom Score (IPSS) and Quality of
Life Scores (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.
    At 6-months post-treatment the mean IPSS values improved by an average of
6.4 points from 19.1 +/- 4.3 at screening to 12.7 +/- 5.2 at day-180 post
treatment (p= 0.0009), with 6 of 15 patients showing a 10 point or greater
improvement in IPSS values. In the 6 men for whom 9-month data are available
at this time, IPSS values improved by an average of 6.1 points. QoL scores
improved by 2.0 points from an average of 4.5 +/- 1.1 at screening to 2.5 +/-
1.4 by day-180 (p= 0.0002). In the 6 men for whom 9-month data is available,
QoL scores improved by an average of 2.3 points by day-270. The mean prostate
volume decreased by over 22%, from 46.4 cc at screening to 35.8 cc at day-180
post-treatment and by 20% from 49.6 cc at screening to 39.7 cc at day-270
    As reported on January 3, 2008, despite a 14-fold escalation in dose, no
safety issues were identified and the maximum tolerated dose was not reached
in this study.
    "We are very pleased to see that the majority of men treated in this
study continue to show very impressive results even 9-months post-treatment,"
said Dr. Fahar Merchant, President and Chief Executive Officer of Protox. "The
sustained symptomatic improvement is compelling especially when a reduction in
IPSS by greater than four points is deemed to be highly clinically
significant. These results further substantiate our belief that PRX302
represents a significant opportunity for the treatment of a condition that
affects the quality of life of approximately 50 percent of men over the age of
    Based on the encouraging data from this study, Protox has initiated a
Phase 2 clinical trial in men with moderate to severe BPH. The intent of this
Phase 2 study will be to optimize dosing in order to fully exploit the
therapeutic potential of PRX302, while maintaining its excellent safety

    About the Study

    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 IPSS throughout
the study, when compared to screening. In addition, changes in QoL scores and
prostate volume were also monitored. A total of 15 patients with moderate to
severe BPH were treated in this trial. The dose was increased 14-fold between
cohort 1 and cohort 4, keeping the dosing volume constant, whereas one
additional cohort received cohort 1 dose at a 4-fold higher volume. Patient
parameters at screening were as follows: age – 64.8 years (range: 52-82);
prostate size – 41.3 mL (range: 30.0-80.1); IPSS – 19.1 (range: 12-26); QoL –
4.3 (range: 3- 6). Most patients treated in this study were either refractory
or intolerant to oral therapy.

    About BPH

    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. 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.

    About Protox

    Protox Therapeutics is a leader in advancing novel, receptor targeted
fusion proteins. Two novel drug candidates derived from the company's INxinTM
and PORxinTM 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 2a clinical trials evaluating PRX302
(PORxin) for the treatment of localized prostate cancer and benign prostatic
hyperplasia (enlarged prostate) have also been initiated. 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

    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.