Prospective, Randomized, Double-Blind, Vehicle-Controlled, Multicenter Phase IIb Clinical Trial of the Pore-Forming Protein PRX302 for Targeted Treatment of Symptomatic Benign Prostatic Hyperplasia
Elhilali MM, Pommerville P, Yocum RC, Merchant R, Roehrborn CG, Denmeade SR. J Urol. 2012 Nov 7. pii: S0022-5347(12)05468-7. doi: 10.1016/j.juro.2012.11.003. [Epub ahead of print]


Department of Surgery, McGill University, Montreal, QC, Canada. Electronic address:



Safety and efficacy evaluation of intraprostatic injection of PRX302, a modified pore-forming protein (proaerolysin) activated by PSA, as a highly-targeted, localized approach treating lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH).


92 patients with International Prostate Symptom Score (IPSS) ≥15, peak urine flow (Q(max)) ≤12 mL/sec, and prostate volume (PV) 30-100 mL were randomized 2:1 to a single ultrasound-guided intraprostatic injection of PRX302 vs. vehicle (placebo) in this Phase IIb double-blind study. Injection was 20% of PV and 0.6 μg PRX302/g prostate. Q(max) was determined by a blinded reviewer. BPH medications were prohibited. The primary dataset of efficacy evaluable patients (EE, N=73) was analyzed, using last observation carried forward.


PRX302 treatment resulted in ~9-point reduction in IPSS and ~3 mL/sec increase in Q(max) that were statistically significant changes from baseline compared to vehicle. Efficacy was sustained over 12 months. Early withdrawal for other BPH treatment was more common for vehicle. Relative to vehicle, PRX302-apparent toxicity was mild, transient, and limited to local discomfort/pain and irritative urinary symptoms occurring within the first few days, with no effect on erectile function.


A single administration of PRX302 as a short, outpatient-based procedure was well-tolerated in patients with LUTS due to BPH. PRX302 produced clinically meaningful and statistically significant improvement in both patient subjective (IPSS) and quantitative objective (Q(max)) measures sustained over 12 months. The side effect profile is favorable with most effects attributed to the injection itself and not related to drug toxicity.