Late stage development of PRX302 is supported by a successful randomized Phase IIb study with standard and well defined regulatory endpoints. PRX302 has shown meaningful improvements in the International Prostate Symptom Score (IPSS) and urinary flow rate (Qmax) at 3 and 6 months in this randomized, double-blind, placebo controlled Phase IIb trial (TRIUMPH). To date 126 patients with BPH have been treated with PRX302, demonstrating an attractive safety profile including no drug-related erectile dysfunction adverse events.

IPSS has been a primary endpoint and Qmax has been a secondary (or co-primary) endpoint for the FDA approval of currently available drugs for the treatment of BPH.

Sophiris is currently conducting a double-blind, multi-center, placebo controlled Phase IIa study in approximately 40 patients with moderate to severe BPH. Patient enrollment is now complete. Patients were randomized to PRX302 or placebo within one of four dose cohorts in this transrectal study. The primary endpoint of the study is to evaluate the 3-month safety and tolerability of escalating doses of PRX302. The safety data from the transrectal route of administration will be compared with the safety profile obtained from the previously conducted studies utilizing the transperineal route. Patients will be followed for up to 12 months.

A multi-center, double blinded, placebo controlled Phase IIb study (TRIUMPH) of PRX302 in men with moderate to severe BPH met its primary endpoint demonstrating a statistically significant improvement in IPSS from baseline when compared to placebo at 3 months post-treatment. In the study, patients treated with PRX302 showed an improvement of 9.1 points from baseline versus an improvement in IPSS of 5.8 points from baseline in patients receiving placebo (p<0.05).

The transperineal administration of PRX302 was well tolerated in these open label and dose-escalation and volume studies, and, IPSS scores improved significantly for up to 12 months after treatment. The dose escalation of 14-fold was well tolerated and the Maximum Tolerated Dose was not reached. No drug-related adverse events Grade 3 or higher were observed. Results supported further development of PRX302.