🏛️ Verified NIH Record • Updated 2026-08-13

A Phase 3 Study of Fenfluramine Hydrochloride in Rett Syndrome (NCT07503444)

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

🟢 Recruiting Phase3 💊 Investigational Drug / Biologic Sponsor: UCB BIOSCIENCES, Inc.

🩺 Plain-English Summary (8th-Grade Level)

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

Who can join: Review the eligibility criteria below.

Location: Ep0247 21010 — Little Rock, Arkansas

Age range: 5 Years to 35 Years

🧪 Interventions in This Study

📋 "Do I Qualify?" — 1-Minute Self Screener

Instant Checklist

Full eligibility criteria are available on the official NIH protocol. View the criteria ↗

📍 All Participating Trial Locations (18 Sites)

  • Ep0247 21010 — Little Rock, Arkansas
  • Ep0247 21011 — Orlando, Florida
  • Ep0247 21007 — Atlanta, Georgia
  • Ep0247 21005 — Houston, Texas
  • Ep0247 21013 — Irving, Texas
  • Ep0247 11001 — Brussels,
  • Ep0247 12005 — Brest,
  • Ep0247 15001 — Budapest,
  • Ep0247 15002 — Debrecen,
  • Ep0247 17006 — Troina,
  • Ep0247 43004 — Kodaira,
  • Ep0247 43006 — Musashimurayama-shi,
  • Ep0247 43002 — Osaka,
  • Ep0247 43003 — Setagaya-ku,
  • Ep0247 19002 — Krakow,
  • Ep0247 11105 — Madrid,
  • Ep0247 11103 — Málaga,
  • Ep0247 11102 — Seville,

📞 Contact the Study Coordinator

Phone: (844) 599-2273

Email: ucbcares@ucb.com

Coordinator details come directly from the registered NIH protocol. Confirm the study is still recruiting before traveling.

💰 Cost, Insurance & Patient Rights

  • 100% Free Items: The investigational treatment and protocol-required procedures are supplied at zero cost by the sponsor.
  • Routine Patient Care: Under federal law (ACA § 2709) and many state statutes, routine care costs are covered during participation.
  • Voluntary Participation: You may withdraw at any time without affecting your standard medical care.

Explore by condition: All Rett Syndrome clinical trials

💡 How to Participate

  1. Check the checklist above to see if you may qualify.
  2. Contact the study coordinator using the phone/email above.
  3. Ask about the visit schedule, what is covered at no cost, and any travel support.
  4. Confirm with your own doctor before making a decision.
🏛️ View Official NIH Record ↗