NCT07157254Phase 2Active not recruiting

A Safety and Efficacy Study of GTX-102 in Subjects With Deletion- or Nondeletion-type Angelman Syndrome (AS)

Study sponsor: Ultragenyx Pharmaceutical Inc · RARE

Compare the available registry edits below. Primary completion is the date data collection ends for the main study measures; it does not tell you when results will be published.

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Primary completion2030-01Estimated

Enrollment · participants60Estimated

Source updated2026-09-09Last update listed in the registry record

Version history

Changes to this trial

Last 12 months

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Posted 2026-09-09 · 1 field changed

Recruitment status changed

− Before

~~Recruiting~~

+ After

Active not recruiting

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Posted 2025-09-30 · 1 field changed

Recruitment status changed

− Before

~~Not yet recruiting~~

+ After

Recruiting

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Study details

Conditions studied

Angelman Syndrome

Treatments or interventions studied

GTX-102DrugAlso known as apazunersen

Primary outcomes · main study measures

Read the study measures

measure: Subprotocol A/B/C/D: Number of Participants with Treatment Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs), Severe Events, and Events Related to Investigational Product, Procedure, and Premedication; timeFrame: Up to Day 506; measure: Subprotocol A Only: Bayley-4 Cognitive Without Caregiver Input Raw Score Change from Baseline at Day 338; timeFrame: Baseline, Day 338; measure: Subprotocol B/D Only: Multidomain Responder Index (MDRI) Net Response at Day 338; description: The following assessments will be included to calculate the MDRI net response: Bayley-4 Cognitive and Receptive Communication, Aberrant Behavior Checklist- Community (ABC-C) Hyperactivity/Noncompliance (H/N), Angelman Severity Assessment (ASA) Sleep, ASA Gross Motor. For each assessment a meaningful score difference (MSD) is defined. A single net response score per participant will be derived accordingly, and a summary measure of net response will then be calculated across all participants.; timeFrame: Baseline, Day 338; measure: Subprotocol C Only: MDRI Net Response at Day 338; description: The following assessments will be included to calculate the MDRI net response: Vineland-3 Expressive and Receptive Communication, ABC-C Irritability, ASA Gross Motor. For each assessment a meaningful score difference (MSD) is defined. A single net response score per participant will be derived accordingly, and a summary measure of net response will then be calculated across all participants.; timeFrame: Baseline, Day 338

History coverage

Research sample: selected versions from May 2023 onward plus a preceding baseline where available. Only selected fields were retained; endpoint measures were truncated to 300 characters. This is not complete trial or sponsor history. Daily snapshots begin when collection starts.

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