News ReleasesPrinter friendly version Protox Completes BPH Trial Recruitment And Announces Positive Interim Data
Vancouver, British Columbia, October 3, 2007 – Protox Therapeutics Inc. (TSX-V:PRX) today announced that it has completed recruitment of patients for its Phase 1 clinical trial evaluating PRX302 in males with benign prostatic hyperplasia (BPH) and reported positive interim data from this study. The findings to date indicate that PRX302 is safe and well tolerated and shows promising signs of therapeutic activity.
“Patients with bladder outlet obstruction and lower urinary tract symptoms due to BPH are keen to seek non-surgical options”, said Dr. Peter Pommerville, co-principal investigator at Can-Med Clinical Research Centre in Victoria, B.C. “Very often they first choose oral medication to relieve their symptoms. The current standard of care is a combination of an alpha-blocker and a 5 alpha-reductase inhibitor. These medications, although effective, take a long period of treatment time to show benefit and can cause significant side effects, such as altering sexual function. The patients with BPH that I have treated with PRX302 consider this to be an excellent alternative to prostate surgery and better than the standard oral therapy because results are almost immediate. PRX302 reduces symptoms without sexual side effects. Nocturia (waking at night to urinate) has been reduced from up to 6 times a night to less than once per night in some patients. The symptom reduction has been maintained in these patients over the period of follow-up.”
“We are very pleased to have completed recruitment of this study ahead of schedule and while it is still early in the clinical program we are very encouraged by these results,” said Dr. Fahar Merchant, President and Chief Executive Officer of Protox.
This study is intended to examine the safety, tolerability and therapeutic activity of PRX302 in patients with moderate to severe BPH. Using a well-established, image-guided technique, PRX302 was administered directly into the prostate in a relatively simple procedure performed in the urologist’s office. A total of 12 patients in four cohorts (three patients per cohort) were treated in this study protocol. The average age of the patients in this study is 62.5 years (range: 52-82). Most of the patients treated in this study were either refractory or intolerant to oral therapy. Protox has concluded that despite a 14-fold escalation in dose, the maximum tolerated dose was not reached in this study. Results indicate that PRX302 is safe and well tolerated with no serious adverse events observed. Any adverse events reported were mild in nature and all transient.
In nine out of 12 patients for whom 30-day data is available at this time, encouraging signs of therapeutic activity were observed. International Prostate Symptom Scores (IPSS) are commonly used to assess the efficacy of therapies used to treat BPH. This symptom index was developed and validated by the American Urological Association and includes seven categories covering frequency, nocturia, weak urinary stream, hesitancy, intermittence, incomplete emptying and urgency. 30-day data has shown a clear and desirable trend towards decreased (improved) IPSS scores. The patients treated at the lowest dose in this study (cohort 1) showed an average one point (5%) decrease in IPSS scores, while those treated at the intermediate doses (cohorts 2 and 3) both averaged seven point decreases of 39% and 35% respectively. Quality of life scores (QOL) are another symptom index used to assess the improvement of patients that have undergone BPH therapy. This index is measured on a scale from 0-6 with 0 defined as “delighted” and 6 defined as “terrible.” At screening, most subjects had QOL scores ranging from 4 to 6, suggesting mostly “dissatisfied”, “unhappy” and “terrible” feelings regarding the state of their urinary symptoms. In all of the nine patients for whom 30-day data is available, QOL scores decreased compared to screening. Patients in cohort 1, 2 and 3 showed an average 54%, 63% and 60% decrease respectively.
Dr. Pommerville added, “The procedure is simple, safe, can be performed in a physicians office and more importantly, the beneficial effects of treatment are observed in less than two weeks. The marked reduction in symptoms has had a profound improvement in patients’ quality of life. The avoidance of surgery and sexual side effects caused by oral therapy, the rapid onset of improvement in obstructive symptoms and allowing patients to get back to their regular routine the day after the procedure appeals to men suffering from this disease. Two patients who are keen golfers were able to play the day after PRX302 treatment, attesting to the simplicity of the procedure.”
The company anticipates that data from cohort 4 (the highest dose) and top-line data from the study will be released before the end of the year and plans to commence a Phase 2 study in early 2008.
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. 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 (2006), the market opportunity for therapies used to treat BPH was US $4.9 billion.
About PRX302
PRX302 is the lead drug in the company’s PORxinTM technology platform. PORxin drugs are 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 to create a potent agent with a distinct mode of action. The drug has been engineered 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.
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™ and PORxin™ 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).
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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 contact:
James Beesley
Director, Investor Relations
Protox Therapeutics
604-688-0199
jbeesley@protoxtherapeutics.com
Michael Moore
Investor Relations
The Equicom Group
416-815-0700 x 241
mmoore@equicomgroup.com
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