Conflict of Interest. This research was supported by Bayer Corporation, Pharmaceutical Division, West Haven, CT, and Bayer Inc, Toronto, CA. Drs. Taylor and Bangerter are employees of Bayer Healthcare.
Purpose. The North American Pivotal Trial was designed to investigate the efficacy and safety of vardenafil in males with erectile dysfunction (ED).
Materials and Methods. In this randomized, double-blind, placebo-controlled, multicenter, fixed-dose, parallel group, 6-month study, vardenafil at three doses (5 mg, 10 mg, and 20 mg) was compared to placebo with the primary efficacy variables being the International Index of Erectile Function (IIEF) Erectile Function (EF) domain score and per patient diary response success rates for penetration and maintenance of erection through completion of intercourse. Additional efficacy variables included IIEF domain scores measuring intercourse satisfaction, orgasmic function, sexual desire, and overall satisfaction. Diary entries for overall per patient satisfaction rates for hardness and sexual experience were also measured. Improvements in quality of sexual life were assessed using the Fugl-Meyer quality of life (QoL) questionnaire.
Results. Compared to placebo, patients taking 10 mg and 20 mg doses of vardenafil showed statistically significantly greater improvement in IIEF domain scores measuring intercourse satisfaction (10.3 and 10.3 vs. 7.7), orgasmic function (7.1 and 6.9 vs. 5.3), overall satisfaction. (7.1 and 7.1 vs. 5.2) for vardenafil 10 mg and 20 mg vs. placebo, respectively, at last observation carried forward (LOCF). Vardenafil 5 mg was statistically significantly better than placebo for the secondary IIEF domain variables of intercourse satisfaction (8.9 vs. 7.7) and overall satisfaction (6.3 vs. 5.2) for vardenafil vs. placebo, respectively, at LOCF. Per patient satisfaction rates for the secondary diary variables measuring erection hardness (38%, 52%, 58% and 18%) and overall satisfaction (45%, 58%, 62% and 23%) were dose dependent and statistically significantly superior for vardenafil at 5 mg, 10 mg and 20 mg compared with placebo, respectively. Patients’ answers to the Fugl-Meyer QoL questionnaire assessing improvement in sexual life also indicated statistically significant superiority for all doses of vardenafil vs. placebo treatment. The most frequent adverse events (AE) in the 5 mg, 10 mg, and 20 mg of vardenafil and placebo groups, respectively, were: headache (10%, 22%, 21% and 4%), flushing (5%, 10%, 13% and 0%), dyspepsia (1%, 4%, 6% and < 1%), and rhinitis (9%, 14%, 17% and 5%). Most AEs were mild or moderate in severity and transient in nature.
Conclusion. Vardenafil was superior to placebo for IIEF domain scores, per patient success rates for diary questions, and assessment of quality of sexual life, in a broad range of patients with ED irrespective of etiology or severity. Vardenafil was generally well tolerated, with most AEs being mild or moderate in severity and transient in nature.