Latest News of Levitra
Wednesday, 27 Sep 2006
Study Demonstrates Preference for Vardenafil (Levitra(R)) in Comparison to Sildenafil
Vardenafil (Levitra(R)) also Achieves Nominal Statistical Superiority to
Sildenafil for Several Frequently Used Efficacy Measures
A new medical study shows that among men with erectile dysfunction and risk factors for cardiovascular disease who expressed a preference, 53% preferred vardenafil (Levitra(R)) compared to 47% who preferred sildenafil.(*1) This study demonstrated nominal statistical superiority to sildenafil for several frequently used efficacy measures and non-inferiority to sildenafil for overall preference. Non- inferiority designs are utilized to assess the efficacy of two compounds when the known efficacy of both vs. a placebo is already well-established. Once non-inferiority is established, superiority can subsequently be tested.
A total of 1057 men with erectile dysfunction and diabetes, hypertension and/or hyperlipidaemia from Europe, USA and Mexico were recruited for the CONFIRMED (COmparing vardeNafil and sildenaFil In the tReatment of Men with Erectile Dysfunction (ED)) Study, a randomised, double-blind, pooled crossover study. 38.9% of patients expressed an overall preference for vardenafil (Levitra(R)) over sildenafil (34.5%), and 26.6% of patients had no treatment preference, confirming the non-inferiority of vardenafil (Levitra(R)).
Vardenafil (Levitra(R)) also achieved nominal statistical superiority to sildenafil for several frequently used efficacy measures, which included questions related to erectile function and sexual performance. For example, 83.9% of patients taking vardenafil (Levitra(R)) responded positively to Sexual Encounter Profile (SEP) question 2 (p=0.0389)(*2) compared with 82.2% for sildenafil, and 74% of patients reported a positive response to vardenafil (Levitra(R)) for the question SEP3 (p=0.0038)(*3) against 72% for sildenafil.
Comparative clinical trials can be difficult to design in an unbiased way. However, the CONFIRMED study is the only head-to-head comparison clinical trial that is consciously designed to minimize the bias seen in other comparative trials published to date by creating a methodology including 13 separate criteria. Trial results that are more likely to be accepted by the medical community are usually randomised (patients are chosen randomly to be given one treatment or the other), double-blind (neither the researcher nor patient know which treatment the patient is taking until the end of the study), cross-over design (each patient tries one treatment and then the other).
This trial additionally used equivalent drug doses, had a randomised treatment sequence, used a neutral consent form, assessed preference after each treatment period and, importantly, did not eliminate previous non-responders or only include naive patients (patients who had never used an ED treatment before).
"The CONFIRMED study represents an important step forward in our understanding of the clinical differences between PDE5 inhibitors, confirming the efficacy of Levitra for men with erectile dysfunction," explained Irwin Goldstein, study co-author and Editor in Chief of the Journal of Sexual Medicine.