Natural History Study in Pediatric Patients with STXBP1 Encephalopathy with Epilepsy

Withdrawn

• Conditions: STXBP1 Encephalopathy with Epilepsy

• Registration Number: NCT05462054
• Lead Sponsor: Capsida Biotherapeutics, Inc.

Brief Summary

This is a prospective, non-interventional, longitudinal study designed to characterize the natural history of STXBP1 related encephalopathy with epilepsy, in participants ≤ \<5 years of age.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2022-07-05
• Study First Submitted QC: 2022-07-13
• Study First Posted: 2022-07-18
• Status Verified: 2024-10
• Study Start: 2024-10
• Last Update Submitted: 2024-10-16
• Last Update Posted: 2024-10-18
• Primary Completion: 2026-01
• Study Completion: 2026-01

Recruitment & Eligibility

• Status: WITHDRAWN
• Sex: All
• Target Recruitment: 20

Inclusion Criteria

• Male or female, > 1 day to ≤ 5 years of age at the time of informed consent.
• Diagnosed with seizure disorder
• Presence of a STXBP1 gene mutation. Historical documentation is sufficient to support eligibility for the study. Confirmatory testing will be obtained at baseline and performed by a CLIA certified laboratory
• Written informed consent provided by a parent or legal guardian

Exclusion Criteria

• History of prior gene therapy treatment
• Current enrollment in an interventional study or has received an investigational drug within 30 days or fewer than 5 half-lives prior to screening visit, whichever is longer
• Treatment with any antisense oligonucleotide therapy within 6 months prior to screening and anticipate remaining on treatment throughout the study
• The presence of a confirmed mutation in a gene other than STXPB1 that is known to contribute to a neurodevelopmental disability
• Presence of a significant non-STXBP1 related central nervous impairment/behavioral disturbance that would confound the scientific rigor or interpretation of results of the study
• History of prematurity (defined as gestational age <35 weeks), interventricular hemorrhage, structural brain deficit or congenital heart disease
• Requires mechanical ventilation or non-invasive respiratory support such as continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP) at the time of informed consent

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Changes in neurodevelopment parameters over time utilizing an age appropriate assessment.	2 Years	The determination of whether a patient received Kaufman Assessment Battery for Children-II (KABC-II) is based on an algorithm that includes the patient's calendar age and VABS-II age-equivalent score (See Outcome 1). The KABC-II is an individually administered measure of processing and reasoning abilities. The scoring range is 69 and below through 131 or greater. Higher scores mean a better outcome.
Changes in seizure frequency over time	2 Years	Seizure diary
Changes in neurodevelopmental parameters of adaptive behavior function over time utilizing the Vineland Adaptive Behavior Scales-II (VABS-II) Age-equivalent Scores	2 Years	The Vineland Adaptive Behavior Scales, Second Edition (Survey Interview Form) is a measure of adaptive behavior in children, adolescents and adults. It yields an overall standard score (Adaptive Behavior Composite, ABC) and age standard scores in four domains. ABC scores have a mean of 100 and a standard deviation of 15 (range = 20 to 160). Higher scores suggest a higher level of adaptive functioning.

Secondary Outcome Measures

Name	Time	Method
Changes in electroencephalogram (EEG) recording over time	2 Years	Standard EEG, lasting approximately 1 hour, to assess the presence of epileptiform activity.
Changes in communication ability over time	2 Years	Observer-Reported Communication Ability (ORCA) Outcome Measure. The ORCA measure produces a single score that is an estimate of an individual's overall level of communication ability. Higher ORCA scores reflect greater communication ability; the mastery of expressive, receptive, and pragmatic types of communication and higher vocabularies for verbal words and symbols on assistive devices. The ORCA T-score range is from 26.82 to 83.24.
Changes in sleep behavior over time	2 Years	Patient sleep habits will be assessed using Children's Sleep Habits Questionnaires (CSHQ).
Changes in motor function over time utilizing an age appropriate assessment.	2 Years	The Gross Motor Function Measure-88 is aimed to be used for children 5 months or older of age and assess changes in gross motor function over time. Each item is scored 0-3, higher scores mean a better outcome.