A Study of Tadalafil After Radical Prostatectomy

A Randomised, Double-Blind, Placebo-Controlled Study to Evaluate the Effect on Unassisted Erectile Function of the Early Use of Tadalafil 5 mg Once a Day and Tadalafil 20 mg On Demand Treatment for 9 Months in Subjects Undergoing Bilateral Nerve-Sparing Radical Prostatectomy

The study will include patients with localized prostate cancer who experience erectile dysfunction following bilateral nerve-sparing radical prostatectomy. Patients will be randomly assigned to three treatment arms: Tadalafil 5 mg once a day, Tadalafil 20 mg on demand (prior to anticipated sexual activity), and placebo. Patients will stay on therapy for 9 months and after withdrawal of medication for 6 weeks, patients will be evaluated for recovery of unassisted erectile function (without medication). An open-label extension for three months will evaluate the responsiveness of all patients to Tadalafil 5 mg once a day. Further objectives are to evaluate the treatment satisfaction of the respective therapies.

Inclusion Criteria:

• scheduled to undergo Bilateral nerve-sparing radical prostatectomy (BNSRP) for organ-confined, non-metastatic prostate cancer
• have a normal preoperative erectile function score of more or equal to 22 at screening(as evaluated by International Index of Erectile Function - Erectile Function domain (IIEF-EF))
• develop Erectile Dysfunction (ED) (defined as the consistent inability to achieve and/or maintain an erection sufficient to permit satisfactory sexual intercourse) after surgery
• have an interest in resuming sexual activity as soon as possible after surgery and anticipate having the same adult female sexual partner during the study
• agree not to use any other treatment for ED, including herbal and over-the-counter (OTC) medications, during the study
• does not require the initiation of adjuvant therapy for prostate cancer

Exclusion Criteria:

• history of ED
• have received previous or current treatment with tadalafil or any other Phosphodiesterase Type 5 (PDE5) inhibitor
• have undergone, or plan to undergo, radiation or hormonal therapy for prostate cancer
• have a history of prostatic surgery or prostatic physical treatments
• have a history of diabetes mellitus
• have a history of galactose intolerance, lapp lactase deficiency, or glucose-galactose malabsorption
• have clinically significant renal insufficiency as determined by the investigator