This Study is to Evaluate the Safety and Efficacy of Avanafil in the Treatment of Erectile Dysfunction.

This study is designed as a double-blind, stratified randomized, placebo controlled, parallel group, multicenter, dose escalation study. For subjects with moderate to severe ED who have voluntarily signed the consent form, conduct screening and undertake the 4 weeks Free run-in period. For those who satisfy the study criteria during the review of subject's diaries composed during the free run-in period and the evaluation of inclusion/exclusion criteria at a future visit, drugs for each group are provided after randomized to Avanafil 100mg or placebo 100mg at a ratio of 2:1. At this time, subjects are random stratified to each group depending on their diabetes status.