The first objective of this study is to demonstrate the efficacy and safety of pitolisant given at 10, 20, or 40 mg per day versus placebo during 12 weeks of the Double Blind period, to treat the Excessive Daytime Sleepiness (EDS) in patients with Obstructive Sleep Apnea (OSA) refusing the nasal Continuous Positive Airway Pressure (nCPAP) therapy or treated by nCPAP but still complaining of EDS.