NNZ-2591 for Phelan-McDermid Syndrome in Children

This study is testing a drug called NNZ-2591 for children with Phelan-McDermid Syndrome. It's an open-label study, meaning everyone knows they are receiving the active drug. The main goal is to see how safe NNZ-2591 is over a long period, looking at any side effects and changes in heart activity (ECG parameters) for up to 12 months. The study plans to enroll 180 children aged 3 to 12 years old who have previously participated in other studies for NNZ-2591. The drug will be given by mouth twice a day.

Study design
This is an open-label extension study, meaning all 180 participants will receive the study drug. It is designed to evaluate the long-term safety and tolerability of NNZ-2591.
What's involved
You would receive NNZ-2591 orally twice daily for 52 weeks. There will be assessments for eligibility, baseline characteristics, and symptom severity, followed by a 2-week safety follow-up period.
Compensation
Not stated in the trial record.
Follow-up
Participants will be followed for safety for 2 weeks after the 52-week treatment period, with safety and heart activity (ECG) monitored for up to 12 months.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT07593391

An Open-label Study of NNZ-2591 in Pediatric Participants With Phelan-McDermid Syndrome

Recruiting
PHASE3Ages 3–12InterventionalTreatment
Neuren Pharmaceuticals Limited
~180 participants
Updated 2026-08-12 on ClinicalTrials.gov
What's tested:NNZ-2591

At a glance

Recruiting sites
6 of 6 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Long-term safety and tolerability of NNZ-2591 as assessed by the incidence of adverse events across participants
Measured over Baseline through Safety Follow-Up (Month 12)
+13 more outcomes measured
Phelan-McDermid Syndrome

NCT07593391

Where you'd take part

This study runs at 6 sites. They're the same protocol — you choose where, and that choice sets who your contact draft is addressed to.

  • Neuren PMS-302 Site#104

    Lexington, Massachusettsstudy coordinator listed

    Recruiting

  • Neuren PMS-302 Site#108

    Cincinnati, Ohiostudy coordinator listed

    Recruiting

  • Neuren PMS-302 Site#109

    Chevy Chase, Marylandstudy coordinator listed

    Recruiting

  • Neuren PMS-302 Site#111

    San Rafael, Californiastudy coordinator listed

    Recruiting

  • Neuren PMS-302 Site#115

    Houston, Texasstudy coordinator listed

    Recruiting

  • Neuren PMS-302 Site#122

    Glendale, Californiastudy coordinator listed

    Recruiting

Sites open and close at different times, so the status above is per site — it can differ from the study's overall status.

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  • Long-term safety and tolerability of NNZ-2591 as assessed by the incidence of adverse events across participantsBaseline through Safety Follow-Up (Month 12)

    Incidence of TEAEs, AESI and SAEs across participants

  • Long-term safety and tolerability of NNZ-2591 as assessed by changes from Baseline assessments of ECG parameters events across participants.Baseline through Month 12

    Change from Baseline in ECG Heart Rate (bpm)

  • Long-term safety and tolerability of NNZ-2591 as assessed by changes from Baseline assessments of ECG parameters events across participants.Baseline through Safety Follow-Up (Month 12)

    Change from Baseline PR Interval (ms QRS interval (ms)

  • Long-term safety and tolerability of NNZ-2591 as assessed by changes from Baseline assessments of ECG parameters events across participants.Baseline through Safety Follow-Up (Month 12)

    Change from Baseline in QT interval (ms)

  • Long-term safety and tolerability of NNZ-2591 as assessed by changes from Baseline assessments of ECG parameters events across participants.Baseline through Safety Follow-Up (Month 12)

    Change from Baseline in QTcB interval (ms)

  • Long-term safety and tolerability of NNZ-2591 as assessed by changes from Baseline assessments of ECG parameters events across participants.Baseline through Safety Follow-Up (Month 12)

    Change from Baseline in QTcF interval (ms)

  • Long-term safety and tolerability of NNZ-2591 as assessed by changes from Baseline assessments of ECG parameters events across participants.Baseline through Safety Follow-Up (Month 12)

    Change from Baseline in RR interval (ms)

  • Long-term safety and tolerability of NNZ-2591 as assessed by changes from Baseline assessments of vital sign parameters events across participants.Baseline through Month 12

    Change from Baseline for heart rate (bpm)

  • Long-term safety and tolerability of NNZ-2591 as assessed by changes from Baseline assessments of vital sign parameters events across participants.Baseline through Month 12

    Change from Baseline for respiration rate (breaths per minute)

  • Long-term safety and tolerability of NNZ-2591 as assessed by changes from Baseline assessments of vital sign parameters events across participants.Baseline through Month 12

    Change from Baseline for Temperature (Celsius)

  • Long-term safety and tolerability of NNZ-2591 as assessed by changes from Baseline assessments of vital sign parameters events across participants.Baseline through Month 12

    Change from Baseline for Diastolic Blood Pressure (mm Hg)

  • Long-term safety and tolerability of NNZ-2591 as assessed by changes from Baseline assessments of vital sign parameters events across participants.Baseline through Month 12

    Change from Baseline for Systolic Blood Pressure (mm Hg)

  • Long-term safety and tolerability of NNZ-2591 as incidence of abnormal, clinically significant clinical laboratory parameters events across participants.Baseline through Month 12

    Incidence of abnormal and clinically significant laboratory parameters

  • Long-term safety and tolerability of NNZ-2591 as incidence of abnormal, clinically significant physical examination findings across participants.Baseline through Month 12

    Incidence of abnormal, clinically significant physical examination findings