Protox Therapeutics Inc., a leader in the development of receptor targeted fusion proteins, announced positive six month data from its double-blind placebo controlled phase 2b study of PRX302 (study name: TRIUMPH) in patients with moderate to severe benign prostatic hyperplasia (BPH) a bothersome urologic condition that affects the quality of life of more than 50 million men worldwide. The study met its primary endpoint in January 2010 with a statistically significant improvement in International Prostate Symptom Score (IPSS) at Day 90 for patients treated with PRX302 versus placebo and requires additional patient assessments at six and twelve months in order to evaluate safety and the durability of response.

"The six month data from the TRIUMPH study continues to be impressive," said Dr Fahar Merchant, president and chief executive officer of Protox. "These data show a sustained improvement in all efficacy measures consistent with the long-term duration of effect observed in earlier studies. The continued increase in peak urine flow rate, or Qmax, was also remarkable and actually improved by an additional twenty percent when compared to Day ninety results. These data further our belief that PRX302 represents a considerable commercial opportunity".

"The TRIUMPH study continues to deliver exciting results indicating that a single administration of PRX302 to patients with BPH is well tolerated and provides symptomatic relief which is sustained for at least six months as evidenced by improved IPSS and QOL scores," said Dr Mostafa M. Elhilali, OC, M.D., Ph.D. Stephen Jarislowsky Chair of Urology at McGill University and Co-Principal, Investigator. "The improvement in IPSS between treatment and placebo arms was a full point better at six months than at three months, though not statistically significant at six months due to an unexpected and noteworthy increase in the standard deviation of the placebo group. Furthermore, statistically significant improvement in peak urine flow rates demonstrates that PRX302 could offer a promising therapeutic option for patients with BPH."

TRIUMPH was a double-blind, placebo-controlled, multi-centre Phase 2b study in subjects with moderate to severe BPH. Enrolment criteria included baseline IPSS scores greater than or equal to 15, a Qmax of less than 12 millilitres per second and a prostate volume between 30 and 100 mL. Each subject was treated with either PRX302 (3 ?g/mL) or placebo at a volume equivalent to 20 percent of the total prostate size via a single ultrasound guided injection into each lobe of the prostate.

The primary clinical endpoint of the study was a statistically significant improvement in IPSS in the PRX302 treatment group when compared to placebo at day 90 post-treatment. IPSS is a validated clinical endpoint used to assess the treatment benefit of BPH therapies in clinical trials. This index is measured on a 0 to 35 scale with 0 being defined as having no symptoms and >15-35, the population in this study, defined as having moderate to severe symptoms.

PRX302 is the lead drug in the company's PORxin 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. Once activated, the drug punches holes in the cells causing the contents to leak out and ultimately cell death.

BPH is a common urological condition characterized by painful and bothersome symptoms that include difficulty in initiating a urine stream, a sense of urgency, dribbling, incomplete emptying of the bladder, waking several times during the night to urinate and sometimes the presence of blood in the urine. More than half of all men will have symptoms of BPH by the age of 60 and as many as 90% may suffer from BPH after the age of 80. Current oral therapies mainly provide symptomatic relief and can trigger a range of side effects including sexual dysfunction and hypotension. It is estimated that in the seven largest global markets approximately 10 million men are treated annually with oral therapies and these products encompass approximately U.S. $4 billion of sales each year. Surgical options, including minimally invasive procedures, can cause sexual dysfunction, incontinence as well as other more serious procedure-related effects. Surgical measures can require hospitalization, significant recovery time and requires catheterization for variable time intervals. Nearly 600,000 surgical procedures are conducted annually in the seven largest markets.