The trial results indicate that PRX302 is safe and well tolerated and shows very promising signs of therapeutic activity for the treatment of benign prostatic hyperplasia (BPH). Despite a 14-fold escalation in dose, no safety issues were identified and the maximum tolerated dose was not reached in this 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 International Prostate Symptom Score (IPSS) throughout the study, when compared to screening. 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.
Therapeutic activity of PRX302 was evaluated at day-30 and day-90 post-treatment using standardized symptom indices, namely, IPSS and Quality of Life (QoL). Treatment related symptomatic relief was rapid and substantial benefits were noticed by day-30 post-treatment. 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. Across all treatment groups, IPSS scores showed a statistically significant improvement from screening to day 30 (p (less than) 0.01) and continued to day 90 post-treatment (p (less than) 0.001).
Based on the encouraging data from this study, plans are currently underway to commence a Phase II BPH clinical trial in the first quarter of 2008.
Fahar Merchant, president and CEO of Protox, said: “In addition to the excellent safety and tolerability profile, PRX302 has demonstrated substantial symptomatic benefit in most patients who failed existing oral therapies.”