NCT07503444

A Phase 3 Study of Fenfluramine Hydrochloride in Rett Syndrome

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

• Status: Not Yet Recruiting
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 200 (estimated)
• Sponsor: UCB BIOSCIENCES, Inc. · Industry
• Sex: All
• Age: 5 Years – 35 Years
• Healthy volunteers: Not accepted

Summary

The purpose of this study is to investigate the efficacy of fenfluramine hydrochloride (HCl) versus placebo in study participants with Rett syndrome (RTT).

Conditions

• Rett Syndrome

Interventions

Type	Name	Description
DRUG	fenfluramine hydrochloride	Oral solution
OTHER	Placebo	Oral solution

Timeline

• Start date: 2026-03-31
• Primary completion: 2028-08-01
• Completion: 2030-11-15
• First posted: 2026-03-31
• Last updated: 2026-03-31

Regulatory

• FDA-regulated drug study