A Phase 1/2 Open-label, Multiple-dose, Dose-escalating Clinical Trial of the Safety and Tolerability of GTX-102 in Pediatric Patients With Angelman Syndrome (AS) (KIK-AS)

  • End date
    Jan 21, 2024
  • participants needed
  • sponsor
    Ultragenyx Pharmaceutical Inc
Updated on 21 October 2022


The primary objective of the study is to evaluate the safety and tolerability of multiple-ascending doses of GTX-102 administered by IT injection to patients with AS.


This is a Phase 1/2, open-label, multiple-dose, study to evaluate the safety, tolerability, and plasma and CSF concentrations of GTX-102 in pediatric patients with AS.

The study includes a monthly dosing period followed by a maintenance period. The duration of study for each patient in the dose escalation phase is anticipated to be approximately 5 months. Patients will then transition to a maintenance period of study where they may receive continued treatment with GTX-102.

This study was previously posted by GeneTX Biotherapeutics, LLC and was transferred to Ultragenyx in July 2022.

Condition Angelman Syndrome
Treatment GTX-102
Clinical Study IdentifierNCT04259281
SponsorUltragenyx Pharmaceutical Inc
Last Modified on21 October 2022


Yes No Not Sure

Inclusion Criteria

Signed informed consent from parent(s) or legal guardian(s)
Documented genetic confirmation of full maternal UBE3A gene deletion causing AS (e.g. DNA methylation testing with either a chromosomal microarray or FISH) in the region of 15q11.2-q13 including class I, II or III)
Age ≥ 4 to ≤ 17 years at screening (in US Age ≥ 4 to < 8 years at screening)
Stable seizure control (defined as clinically stable with no changes in antiepileptic medications over the prior 1 month before screening visit, other than weight associated dose adjustments)
Platelet count, prothrombin time (PT) / international normalized ratio (INR) and partial thromboplastin time (PTT) within normal limits
Normal renal function with serum creatinine and spot urine protein within normal limits
Normal hepatic function with total bilirubin, aspartate aminotransferase (AST),alanine aminotransferase (ALT) and alkaline phosphatase within normal limits
Willing and able to comply with scheduled visits, drug administration plan, laboratory tests, study restrictions, and all study procedures LP
Able to tolerate the anesthetic regimen required for LP procedure

Exclusion Criteria

Any change in medications (excluding antiepileptic drugs) or diet intended to treat symptoms of AS (e.g. sleeping aids, supplements, ketogenic or low-glycemic index diet, other) over the prior 1 month before screening
Inability to ambulate independently or with an assistive device or caregiver hand-hold
Any bleeding or platelet disorder
Any clinically significant (CS) cardiovascular, endocrine, hepatic, renal, pulmonary, gastrointestinal, neurologic, malignant, metabolic, psychiatric, or other condition that, in the judgment of the Investigator, will pose a safety risk, will make the patient unsuitable for participation in, and/or unable to complete the study procedures
Any laboratory abnormality, that, in the Investigator's opinion, could adversely affect the safety of the patient, make it unlikely that the course of treatment or follow up would be completed, or impair the assessment of study result
Any active infection
Bone, spine, bleeding, or other disorder that exposes the patient to risk of injury or unsuccessful lumbar puncture
Drugs that increase the risk of bleeding (e.g. heparin, low molecular weight heparin, platelet inhibitors)
Use of any investigational oligonucleotide in the past 6 months (with the exception of GTX-102)
Any prior use of gene therapy
Use of any investigational drugs in the past 6 months (with the exception of GTX-102)
Any medical condition that would require intubation for the anesthesia procedure
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