Vardenal 20-mg demonstrated superior efcacy to 10-mg in Japanese men with diabetes mellitus suffering from erectile dysfunction

Aim: Vardenal is a highly selective and potent phosphodiesterase type-5 inhibitor for the treatment of erectile dysfunction (ED). The efcacy of vardenal has been demonstrated in a broad range of ED populations, but has not yet been assessed in Japanese patients with diabetes mellitus (DM), although DM is frequently associated with difcult-to-treat ED. This is the rst study to investigate whether high-dose vardenal (20 mg) can demonstrate superior efcacy to the usual dose (10 mg) in this subpopulation in Japan. Methods: The study was a randomized, placebo-controlled, double-blind, multi-centre, parallel group comparison 12-week study. Following 4 weeks observation period, 778 patients aged 26-64 years old with ED and DM (HbA1c > 12% at screening was excluded) both of more than 3 years duration were randomly allocated to one of the three groups, vardenal 10 mg, 20 mg, or placebo (randomization ratio 3:3:1). Erectile function (EF) domain score of the International Index of Erectile Function was estimated as the primary efcacy parameter. Results: Vardenal 10 and 20 mg both signicantly improved the EF domain score from 13.6 and 13.9 at baseline to 21.8 and 22.9 at last observation carried forward (LOCF), respectively, compared to placebo (13.7 at baseline to 16.3 at LOCF; p < 0.0001). In addition, vardenal 20 mg demonstrated superior efcacy to 10 mg (p < 0.05), and the difference was more evident in severe ED patients (baseline EF domain score < 11). The safety prole was comparable between these two doses (drug-related adverse events: 6.6, 22.0 and 24.2% in placebo, vardenal 10 mg, and 20 mg arms, respectively). The most common adverse events were hot flush, headache and nasal congestion, which were mild in intensity and transient, and are known to be common to PDE5 inhibitors. Conclusion: In Japanese men with DM and ED, vardenal 10 mg and 20 mg were effective in improving erectile function with comparable safety proles. Vardenal 20 mg demonstrated superior efcacy compared with 10 mg, suggesting incremental clinical benet in using the higher dose in this difcult-to-treat population.