NNZ-2591 in kids with Phelan-McDermid syndrome

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This is a Phase 3, open-label extension study evaluating long-term safety, tolerability, and potential efficacy of NNZ-2591 in pediatric participants who previously completed related studies. Eligible children aged 3 to 12 with Phelan-McDermid syndrome will receive oral NNZ-2591 for 52 weeks, with a 2-week safety follow-up after the treatment period. Assessments focus on baseline characteristics, symptom severity, and ongoing safety monitoring across multiple centers. Prior participants from NEU-2591-PMS-301 and NEU-2591-PMS-001 are invited to enroll if eligible. The trial excludes unstable regimens and certain seizure-related medication scenarios to ensure safety.

Why it matters

Who can join: the full rules

Inclusion Criteria:

1. Male or female pediatric participants with Phelan-McDermid syndrome ages 3 to 12 years (inclusive) at the time of signing the informed consent for the antecedent study.
2. Participant must have completed all applicable study visits for the antecedent study in which they participated.
3. Body weight ≥ 10 kg at Screening/Baseline.
4. Participants with a PMSA-S overall score ≥ 3 at the Screening and Baseline visits.
5. Not actively undergoing regression or loss of skills.

Exclusion Criteria:

1. Use of exclusionary medication or unstable treatment regimens of acceptable concomitant medications as required by the protocol.
2. Participants with seizures must be controlled on no more than 2 anticonvulsant medications (not counting rescue medications).
3. Psychotropic medications or any other medication used for a chronic illness (not including antibiotics, pain relievers, anti-diarrheals, and laxatives) with doses and dosing regimen that have not been stable for at least 4 weeks before Screening. If the treatment was discontinued, the discontinuation must have occurred no fewer than 2 weeks before the start of Screening.
4. Any intercurrent seizures in the past 6 months and /or more than 1 seizure in the past 12 months. •A single febrile seizure in the 6 months prior to screening is allowable if no rescue medication was required.
5. Abnormal liver function laboratory results during the Screening period, as defined by the protocol
6. Abnormal QT interval on Screening ECG as defined by the protocol.

Where it's running

• Neuren PMS-302 Site #116
  Birmingham, Alabama, United States Recruiting
• Neuren PMS-302 Site#122
  Glendale, California, United States Recruiting
• Neuren PMS-302 Site#103
  San Diego, California, United States Recruiting
• Neuren PMS-302 Site#111
  San Rafael, California, United States Recruiting
• Neuren PMS-302 Site#102
  Chicago, Illinois, United States Recruiting
• Neuren PMS-302 Site#109
  Chevy Chase, Maryland, United States Recruiting

Study contacts

• Study coordinator: Medical Information Lead
• Email: medicalinformation@neurenpharma.com
• Phone: 231-203-8050

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

• NNZ-2591 for children with Phelan-McDermid syndrome

  This randomized, placebo-controlled trial will test whether NNZ-2591 helps children ages 3–12 with Phelan-McDermid syndrome over a 13-week treatment period.

  Recruiting at 18 sites Phase 3 Neuren Pharmaceuticals Limited · Birmingham, Alabama and 17 other locations · NCT07281079

• Gene therapy for children and adults with SHANK3 haploinsufficiency

  This study is testing a new gene therapy for children and possibly adults with SHANK3 haploinsufficiency to see if it is safe and helps improve their condition.

  Recruiting at 3 sites Phase 1/2 Jaguar Gene Therapy, LLC · Chicago, Illinois and 2 other locations · NCT06662188

How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.