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

NCT ID: NCT07157254

Last Updated: 2025-11-12

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

RECRUITING

Clinical Phase

PHASE2

Total Enrollment

60 participants

Study Classification

INTERVENTIONAL

Study Start Date

2025-10-13

Study Completion Date

2030-01-31

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

The main goal of the study is to evaluate the safety and efficacy of GTX-102 in participants with Angelman syndrome.

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

This basket study is designed to evaluate safety and efficacy of GTX-102 in participants with Angelman syndrome across genotypes and age groups. The study consists of subprotocols A, B, C and D. All subprotocols are open-label and follow the same design which includes a Screening, Loading and Maintenance period. Subprotocols A, B and C are single arm only. In subprotocol D, participants are randomized 2:1 to a GTX-102 group or a No Treatment group. The No Treatment group follows the same schedule of events as all other groups after completion of the No Treatment period. Participants from all the subprotocols have the option to continue treatment in a long-term extension study following their end of study visit.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Angelman Syndrome

Keywords

Explore important study keywords that can help with search, categorization, and topic discovery.

Angelman Syndrome

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

Subprotocol A GTX-102

Participants with deletion-type Angelman syndrome, ≥1 to \<4 years of age will receive increasing doses of GTX-102 via intrathecal (IT) injection until the target dose is achieved. Dosing occurs every 3 months (Q3M) thereafter.

Group Type EXPERIMENTAL

GTX-102

Intervention Type DRUG

antisense oligonucleotide

Subprotocol B GTX-102

Participants with paternal uniparental disomy (UPD)/imprinting center defect (ICD) Angelman syndrome, ≥4 to \<18 years of age will receive increasing doses of GTX-102 via IT injection until the target dose is achieved. Dosing occurs Q3M thereafter.

Group Type EXPERIMENTAL

GTX-102

Intervention Type DRUG

antisense oligonucleotide

Subprotocol C GTX-102

Participants with all genotypes of Angelman syndrome, ≥18 to \<65 years of age will receive increasing doses of GTX-102 via IT injection until the target dose is achieved. Dosing occurs Q3M thereafter.

Group Type EXPERIMENTAL

GTX-102

Intervention Type DRUG

antisense oligonucleotide

Subprotocol D GTX-102

Participants with mutation-type Angelman syndrome, ≥4 to \<18 years of age will receive increasing doses of GTX-102 via IT injection until the target dose is achieved. Dosing occurs Q3M thereafter.

Group Type EXPERIMENTAL

GTX-102

Intervention Type DRUG

antisense oligonucleotide

Subprotocol D No Intervention then GTX-102

Participants with mutation-type Angelman syndrome, ≥4 to \<18 years of age will receive no treatment during the initial period. At the end of the no treatment period, participants will receive increasing doses of GTX-102 via IT injection until the target dose is achieved. Dosing occurs Q3M thereafter.

Group Type EXPERIMENTAL

No intervention

Intervention Type OTHER

During the no treatment period participants do not receive any study drug

GTX-102

Intervention Type DRUG

antisense oligonucleotide

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

No intervention

During the no treatment period participants do not receive any study drug

Intervention Type OTHER

GTX-102

antisense oligonucleotide

Intervention Type DRUG

Other Intervention Names

Discover alternative or legacy names that may be used to describe the listed interventions across different sources.

apazunersen

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

1. Signed informed consent from parent(s) or legal guardian(s)
2. Males and females of the following ages and genotypes at time of informed consent:

1. Subprotocol A: ≥ 1 to \< 4 years of age with a genetically confirmed diagnosis of deletion-type Angelman syndrome
2. Subprotocol B: ≥ 4 to \< 18 years of age with a genetically confirmed diagnosis of UPD/ICD Angelman syndrome
3. Subprotocol C: ≥ 18 to \< 65 years of age with a genetically confirmed diagnosis of Angelman syndrome, any genotype
4. Subprotocol D: ≥ 4 to \< 18 years of age with a genetically confirmed diagnosis of mutation-type Angelman syndrome
3. Weight ≥ 8 kg at Screening Visit
4. Platelet count, prothrombin time / international normalized ratio, and partial thromboplastin time \< 1.5x the upper limit of normal and platelets \> 75,000 cells/mm3 at the Screening Visit
5. Willing and able to comply with scheduled visits, drug administration plan, laboratory tests, and all study procedures, including lumbar puncture (LP) procedure, magnetic resonance imaging (MRI) and tolerating anesthesia without intubation
6. From the time of informed consent through to at least 6 months after the final dose of GTX-102, females of childbearing potential who are sexually active must use highly effective contraception or abstinence. Males are able to participate if they agree to remain abstinent (refrain from heterosexual intercourse) or use acceptable contraceptive methods during the study and for at least 3 months after the final dose of GTX-102

Exclusion Criteria

1. Any change in medications or diet/supplements intended to treat symptoms of Angelman Syndrome (eg, sleeping aids, antiseizure medications, supplements, dietary change including ketogenic or low-glycemic index diet, other) within the month prior to the Screening Visit (excluding weight-based adjustments)
2. Any condition that creates an increased risk of unsuccessful lumbar puncture
3. Current or expected concomitant use of drugs that increase the risk of bleeding (eg, heparin, low molecular weight heparin, platelet inhibitors)
4. Known hypersensitivity to GTX-102 or its excipients or required premedication that, in the judgment of the Investigator, places the subject at increased risk for adverse effects
5. Presence or history of any condition, lab abnormality, or infection that, in the judgment of the Investigator, would interfere with study participation, pose undue safety risk, or would confound interpretation of results
6. Pregnant or breastfeeding or planning to become pregnant (self or partner) at any time during the study
7. Use of any investigational product or investigational medical device within 6 months or 5 half-lives prior to the Screening Visit, or any prior use of gene therapy or an ASO regardless of length of time since last use
8. Concurrent participation in any interventional study
Minimum Eligible Age

1 Year

Maximum Eligible Age

64 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

Meet the organizations funding or collaborating on the study and learn about their roles.

Ultragenyx Pharmaceutical Inc

INDUSTRY

Sponsor Role lead

Responsible Party

Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.

Responsibility Role SPONSOR

Principal Investigators

Learn about the lead researchers overseeing the trial and their institutional affiliations.

Medical Director

Role: STUDY_DIRECTOR

Ultragenyx Pharmaceutical Inc

Locations

Explore where the study is taking place and check the recruitment status at each participating site.

Clinical Trial Site

Los Angeles, California, United States

Site Status NOT_YET_RECRUITING

Clinical Trial Site

Chicago, Illinois, United States

Site Status NOT_YET_RECRUITING

Clinical Trial Site

Baltimore, Maryland, United States

Site Status NOT_YET_RECRUITING

Clinical Trial Site

Kansas City, Missouri, United States

Site Status NOT_YET_RECRUITING

Rare Disease Research

Hillsborough, North Carolina, United States

Site Status RECRUITING

Akron Children's Hospital

Akron, Ohio, United States

Site Status RECRUITING

Clinical Trial Site

Philadelphia, Pennsylvania, United States

Site Status NOT_YET_RECRUITING

Clinical Trial Site

Austin, Texas, United States

Site Status NOT_YET_RECRUITING

Carum Research Inc.

Dallas, Texas, United States

Site Status RECRUITING

Clinical Trial Site

Pilar, Buenos Aires, Argentina

Site Status NOT_YET_RECRUITING

Clinical Trial Site

Curitiba, Paraná, Brazil

Site Status NOT_YET_RECRUITING

Clinical Trial Site

Santa Cecília, Porto Alegre, Brazil

Site Status NOT_YET_RECRUITING

Clinical Trial Site

Marseille, , France

Site Status NOT_YET_RECRUITING

Clinical Trial Site

Paris, , France

Site Status NOT_YET_RECRUITING

Clinical Trial Site

Ramat Gan, , Israel

Site Status NOT_YET_RECRUITING

Clinical Trial Site

Florence, , Italy

Site Status NOT_YET_RECRUITING

Clinical Trial Site

Milan, , Italy

Site Status NOT_YET_RECRUITING

Clinical Trial Site

Rome, , Italy

Site Status NOT_YET_RECRUITING

Clinical Trial Site

Lisbon, , Portugal

Site Status NOT_YET_RECRUITING

Clinical Trial Site

Porto, , Portugal

Site Status NOT_YET_RECRUITING

Clinical Trial Site

London, , United Kingdom

Site Status NOT_YET_RECRUITING

Clinical Trial Site

Oxford, , United Kingdom

Site Status NOT_YET_RECRUITING

Countries

Review the countries where the study has at least one active or historical site.

United States Argentina Brazil France Israel Italy Portugal United Kingdom

Central Contacts

Reach out to these primary contacts for questions about participation or study logistics.

Patients Contact Trial Recruitment

Role: CONTACT

Phone: 1-888-756-8657

Email: [email protected]

HCPs Contact: Medical Information

Role: CONTACT

Phone: 1-888-756-8657

Email: [email protected]

Related Links

Access external resources that provide additional context or updates about the study.

Other Identifiers

Review additional registry numbers or institutional identifiers associated with this trial.

2024-519393-39-00

Identifier Type: CTIS

Identifier Source: secondary_id

GTX-102-CL210

Identifier Type: -

Identifier Source: org_study_id