The purpose of this study is to determine if transurethral photodynamic therapy with lemuteporfin has a therapeutic effect on lower urinary tract symptoms due to an enlarged prostate.

Photodynamic therapy (known as "PDT") is a treatment that uses light to make a drug work. This means the drug is "light-activated". Light-activated drugs do not work until a certain color of light shines on the drug. When the drug and the light combine, they react together to destroy tissue.

This study is investigating PDT with lemuteporfin as a possible treatment for an enlarged prostate. PDT with lemuteporfin may destroy overgrown prostate tissue and help urinary symptoms go back to normal.

This is a multi-center, randomized, sham-controlled, double-blind, dose-finding study in parallel groups of subjects with lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH). All subjects will receive a fixed dose of lemuteporfin injected transurethrally into the prostate followed by transurethral application of either one of three active light doses or a sham light dose. Subjects will be followed for safety and efficacy for a minimum of three months to a maximum of 12 months. The primary study endpoint will be the change from baseline in AUA SI score at three months.

Inclusion Criteria:

• Men 21 years of age and older.
• Subjects with LUTS due to BPH with AUA SI scores of 13 and over and Qmax between 5 and 15 mL/sec.
• Subjects with urethral treatment length of at least 25 mm.

Exclusion Criteria:

• Subjects who have had previous minimally invasive or surgical treatment for BPH.
• Subjects who have unsuitable prostate dimensions.