Efficacy and Safety of Pitolisant in Pediatric Narcoleptic Patients With or Without Cataplexy, Double-blind Study Followed by a Prolonged Open-label Period

Inclusion Criteria: * Male and female children from 6 to less than 18 years of age suffering from narcolepsy with or without cataplexy - ICSD-3 criteria (narcolepsy type 1 and 2). * PDSS * Patients should be free of non-authorized medication, in particular psychostimulant treatments as from the screening visit onwards. * Parents - and patients old enough to understand who have expressed a willingness to participate in the study, who have signed and dated the informed consent form prior to beginning protocol required procedures. * In the opinion of the investigator, the patient must have adequate support to comply with the entire study requirements as described in the protocol (e.g., transportation to and from trial site, self rating scales and diaries completion, drug compliance, scheduled visits, tests). Exclusion Criteria: * Any other conditions that can be considered the primary causes of EDS. * Cataplectic patients treated by anticataplectics which are not under a stable treatment at the time of inclusion. * Patients treated for cataplexy or any other pathology, by tricyclic antidepressants. * Any significant abnormality of the electrocardiogram and particularly Fridericia's QTc interval. * Patients with significant abnormality or clinical laboratory results. * Psychiatric and neurological disorders in the investigator's opinion, would preclude the patient's participation and completion of this trial or comprise reliable representation of subjective symptoms. * Active clinically significant illness, including unstable cardiovascular, endocrine, neoplastic, gastrointestinal, haematological, hepatic, immunologic, metabolic, neurological (other than narcolepsy/cataplexy), pulmonary, and/or renal disease which could interfere with the study conduct or counter-indicate the study treatments or place the patient at risk during the trial or compromise the study objectives.