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ClinicalTrials.gov 6 recruiting now early-phase tilt small index

Angelman Syndrome: early-phase trial registry

6 of 12 indexed Angelman Syndrome trials are currently recruiting, with more weight in Phase 1-2.

Corpus placement: #1,429 of 28,707 conditions by registered trial count.

12 US clinical trials · 6 currently recruiting · #1,429 of 28,707 conditions by registered trial count

Angelman Syndrome: 12 US clinical trials tracked, 6 recruiting.

Angelman Syndrome is the subject of 12 registered US clinical trials on ClinicalTrials.gov, 6 of them currently open to new participants. 2 are in Phase 3-4 (later-stage) and 5 in Phase 1-2 (earlier-stage). The most active sponsor is Ultragenyx Pharmaceutical, running 2 of these trials.

Enrollment posture brief

Registry condition angelman-syndrome

OPEN 6 | RECR 50% | LATE 2 | EARLY 5 | RANK #1429 | SPON 2

Nearest open-share peer: Abdominal Aortic Aneurysms (50% recruiting · 6 trials)

Angelman Syndrome (this)50%Acute Myeloid Leukemia in Re41.7%Adenocarcinoma of the Rectum41.7%Adherence, Patient16.7%Accelerated Phase Chronic My0%
Open-enrollment share among volume-matched conditions near Angelman Syndrome

Angelman Syndrome lists 6 open slots (50% of 12 indexed trials). Peers are matched on registered volume, not therapeutic-area browse lists. How peer matching works →

Key findings

What ClinicalTrials.gov does not surface for Angelman Syndrome on its own pages , computed from the registry mirror as of 2026-08-08. Each line carries its own denominator so it can be quoted as it stands.

  1. Angelman Syndrome is recruiting above its size-band peers.

    6 of 12 indexed trials (50%) are open to enrollment, against a 46.5% average across 27,806 conditions with fewer than 20 trials. The peer set uses the same ClinicalTrials.gov-derived counts as this page.

  2. One sponsor concentrates Angelman Syndrome research.

    Ultragenyx Pharmaceutical accounts for 2 of 12 trials (16.7%). 9 distinct sponsors appear on at least one study for this condition label.

  3. Most Angelman Syndrome trials plan to enrol fewer than 100 people.

    Median target enrolment is 90 among the 12 trials that report a genuine target (sentinel values excluded). 8 of those (66.7%) plan for fewer than 100 participants.

  4. Angelman Syndrome research is mostly interventional.

    10 interventional and 2 observational studies make up this index (83.3% interventional). Study type is sponsor-reported on ClinicalTrials.gov.

Phase 13Phase 22Phase 32

Open and recent trials

12 total, page 1 of 1

RECRUITING 300 participants

Angelman Syndrome Natural History Study

Boston Children's Hospital

NCT04507997

RECRUITING Phase 3 158 participants

REVEAL: A Phase 3 Study of ION582 in Angelman Syndrome

Ionis Pharmaceuticals

NCT06914609

RECRUITING NA 92 participants

Web Intervention for Parents of Youth With Genetic Syndromes (WINGS)

Rush University Medical Center

NCT06139172

RECRUITING Phase 1 70 participants

HALOS: A Safety, Tolerability, Pharmacokinetics and Pharmacodynamics Study of Multiple Ascending Doses of ION582 in Participants With Angelman Syndrome

Ionis Pharmaceuticals

NCT05127226

RECRUITING Phase 2 60 participants

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

Ultragenyx Pharmaceutical

NCT07157254

RECRUITING Phase 1 12 participants

A Phase 1/2 Study of the Safety and Efficacy of MVX-220 in Angelman Syndrome

MavriX Bio

NCT07181837

ACTIVE NOT RECRUITING Phase 3 129 participants

Phase 3 Efficacy and Safety Study of GTX-102 in Pediatric Subjects With Angelman Syndrome (AS)

Ultragenyx Pharmaceutical

NCT06617429

COMPLETED 302 participants

Characterization of Angelman Syndrome

Boston Children's Hospital

NCT00296764

COMPLETED NA 90 participants

Dietary Supplements for the Treatment of Angelman Syndrome

University of California, San Diego

NCT00348933

COMPLETED Phase 2 88 participants

A Study in Adults and Adolescents With Angelman Syndrome (STARS)

Healx AI

NCT02996305

COMPLETED Phase 1 74 participants

A Study to Investigate the Safety, Tolerability, Pharmacokinetics (PK) and Pharmacodynamics (PD) of RO7248824 in Participants With Angelman Syndrome (AS)

Hoffmann-La Roche

NCT04428281

COMPLETED NA 15 participants

Nutritional Formulation for Angelman Syndrome

University of Colorado, Denver

NCT03644693

Phase Distribution

PhaseTrial count
Phase 1 3
Phase 2 2
Phase 3 2

Named interventions

Most-linked intervention names on Angelman Syndrome records (sponsor-reported on ClinicalTrials.gov). Counts are trial links, not unique products.

GTX-102 Drug
2 trials
ION582 Drug
2 trials
RO7248824 Drug
1 trials
Placebo Formulation Dietary supplement
1 trials
Nutritional Formulation Containing Exogenous Ketones Dietary supplement
1 trials
OV101 regimen 2 Drug
1 trials
OV101 Regimen 1 Drug
1 trials
Vitamin B12 Drug
1 trials

US sites by state

Facility locations filed on Angelman Syndrome trials. A trial with sites in several states counts in each.

California 10 trials
Illinois 9 trials
Massachusetts 8 trials
Texas 7 trials
North Carolina 6 trials
Colorado 5 trials
Tennessee 4 trials
Ohio 4 trials

Source: ClinicalTrials.gov, National Library of Medicine. Data is informational only.

What to do with this Angelman Syndrome page

12 registered trials, 6 currently recruiting, is a starting point for a conversation, not a diagnosis or a recommendation.

Trial and recruiting counts reflect ClinicalTrials.gov registry status as of the data vintage above; individual trial eligibility and enrollment status can change.

Every figure on PlainTrial is rendered directly from the ClinicalTrials.gov registry, no number is typed in by an editor. This Angelman Syndrome condition card totals 12 registered trials; most-linked intervention GTX-102; top US site state California. See our editorial standards & corrections policy, the methodology behind these numbers, the data changelog, or report a data error.