Overview Fontan Udenafil Exercise Longitudinal Assessment Trial Status: Completed Trial end date: 2019-04-30 Target enrollment: Participant gender: Summary This study will evaluate the clinical efficacy and safety of udenafil, an orally administered, potent and selective inhibitor of PDE5, versus placebo for the treatment of adolescent subjects who have undergone the Fontan procedure. Phase: Phase 3 Details Lead Sponsor: Mezzion Pharma Co. LtdCollaborator: National Heart, Lung, and Blood Institute (NHLBI)Treatments: Udenafil