Lilly ICOS LLC, a joint venture between Eli Lilly and Company and ICOS Corporation's double-blind, placebo-controlled clinical study of tadalafil in the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia (BPH) achieved positive results. The Phase 2 proof-of-concept study demonstrated clinically meaningful and statistically significant improvement in the primary endpoint, the International Prostate Symptom Score (IPSS), a seven-item questionnaire that assesses the severity of symptoms of BPH and the response to therapy.

The IPSS is the standard scale used for the evaluation of medications that treat the symptoms of BPH. In addition, tadalafil demonstrated statistically significant improvement relative to placebo on most of the secondary endpoints included in the study.

In this Phase 2 study, the most frequently reported side effects were dyspepsia, back pain and headache. None of these side effects was reported by more than 5 per cent of the study participants. There were no serious adverse events determined to be related to drug therapy. The reported adverse events were generally similar in this once-a-day study to those reported in other studies with tadalafil when administered on an as needed basis. The discontinuation rate due to adverse events was 3.6 per cent for patients on tadalafil versus 1.4 per cent on placebo, claims a company release.

Paul Clark, ICOS chairman, president and CEO said, "BPH is a large market with room for new therapies that have a different mechanism of action. Investment in this indication makes a great deal of sense for Lilly ICOS, since many physicians treating patients for the current approved use of tadalafil also treat patients with BPH. We look forward to beginning the Phase 3 studies and confirming these results."

Claus Roehrborn, professor and chair of Urology, University of Texas, Southwestern Medical Center, Dallas, stated, "Millions of men over the age of 45 suffer from lower urinary tract symptoms and BPH. The prospect of having an additional treatment option for these bothersome urinary symptoms is most welcome news for those physicians engaged in caring for the aging male."

Benign enlargement of the prostate gland or BPH can cause a number of troublesome urinary tract symptoms as a man ages. The enlarged prostate gland can irritate the bladder and it can also exert pressure upon the urethra, which is the passageway for urine leaving the bladder.

Tadalafil is an inhibitor of the phosphodiesterase (PDE) type 5 and may cause relaxation of the smooth muscle within the prostate.