Sophiris Bio Inc. is a clinical-stage biopharmaceutical company. The Company is focused on developing products for the treatment of urological diseases. The Company is developing topsalysin (PRX302) as a treatment for the lower urinary tract symptoms of benign prostatic hyperplasia (BPH) commonly referred to as an enlarged prostate and as a treatment for localized low to intermediate risk prostate cancer. Topsalysin, a genetically modified recombinant protein, is delivered through ultrasound-guided injection directly into the prostate. This membrane-disrupting protein is selectively activated by enzymatically active prostate specific antigen (PSA), which is only present in the prostate, leading to localized cell death and tissue disruption without damage to neighboring tissue and nerves. This method of administration limits the circulation of the drug in the body. The Company has completed Phase III clinical trials of topsalysin.