A Phase 3 randomized, double-blind, placebo-controlled, parallel group, multicenter study with open-label extension to evaluate the efficacy and safety of fenfluramine hydrochloride in study participants with Rett syndrome

Trial status: Authorised Change from Baseline to Week 14 in Patient-Reported Outcomes Measurement Information System-Sleep Disturbance (PROMIS-SD) score, Change from Baseline to Week 14 in Observer-Reported Communication Ability (ORCA) score, Caregiver Global Impression of Change – Seizure (CaGIC-Seizure) score at Week 14, Incidence of Treatment-emergent adverse event (TEAEs), Incidence of serious TEAEs, Incidence of TEAEs leading to discontinuation, Incidence of related TEAEs, Change from Baseline in QT interval corrected using Fridericia’s formula (QTcF) interval on 12-lead ECG at Week 14, Treatment-emergent Doppler Echocardiogram (ECHO) results meeting the Food and Drug Administration (FDA) case definition of drug-associated valvular heart disease (VHD), Treatment-emergent Doppler ECHO results meeting the FDA case definition of pulmonary arterial hypertension (PAH) >35mmHg Change from Baseline to Week 14 in Rett Syndrome Behaviour Questionnaire (RSBQ) Total Score, Clinical Global Impression of Change (CGIC) Score at Week 14

Change from Baseline to Week 14 in Patient-Reported Outcomes Measurement Information System-Sleep Disturbance (PROMIS-SD) score, Change from Baseline to Week 14 in Observer-Reported Communication Ability (ORCA) score, Caregiver Global Impression of Change – Seizure (CaGIC-Seizure) score at Week 14, Incidence of Treatment-emergent adverse event (TEAEs), Incidence of serious TEAEs, Incidence of TEAEs leading to discontinuation, Incidence of related TEAEs, Change from Baseline in QT interval corrected using Fridericia’s formula (QTcF) interval on 12-lead ECG at Week 14, Treatment-emergent Doppler Echocardiogram (ECHO) results meeting the Food and Drug Administration (FDA) case definition of drug-associated valvular heart disease (VHD), Treatment-emergent Doppler ECHO results meeting the FDA case definition of pulmonary arterial hypertension (PAH) >35mmHg

Age group: 0-17 years, 18-64 years Gender: Female, Male Target enrollment: 60 participants