International CDKL5 Clinical Research Network

Study Overview
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Brief Summary
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Pathogenic variants in the Cyclin-dependent kinase like 5 (CDKL5) gene cause CDKL5 deficiency disorder (CDD, MIM 300672, 105830), a severe developmental and epileptic encephalopathy associated with cognitive and motor impairments and cortical visual impairment. While capability for disease modifying therapies is accelerating, there is a critical barrier for clinical trial readiness that may result in failure of these therapies, not due to lack of efficacy but due to lack of validated outcome measures and biomarkers. The measures and biomarkers validated here will be adaptable to other developmental and epileptic encephalopathies.

Detailed Description
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Pathogenic variants in the Cyclin-dependent kinase like 5 (CDKL5) gene cause CDKL5 deficiency disorder (CDD, MIM 300672, 105830) a severe developmental and epileptic encephalopathy (DEE) associated with cognitive and motor dysfunction and cortical visual impairment. Recent data suggest CDD is one of the most common genetic causes of DEE. Work in CDD animal models has demonstrated the ability for disease modification and symptom reversal: worldwide efforts are now underway to develop therapeutic strategies (including gene therapy) to treat and potentially cure CDD. While there are four active clinical trials, none assesses the full spectrum of this DEE to address true disease modification. While capability for disease modifying therapies is accelerating, there is a critical barrier for clinical trial readiness that may result in failure of these therapies, not due to lack of efficacy but due to lack of validated outcome measures. CDD has been associated historically with Rett syndrome but there are many clear distinctions and CDD has emerged as an independent disorder. Some Clinical Outcome Measures (COMs) can be adapted from Rett syndrome COMs, whereas others need to be developed specifically for CDD. Our research network is uniquely positioned to develop clinical trial readiness for CDD by pairing exceptional experience in the development and validation of outcome measures with an extensive network of CDD experts and clinical trialists. Our goals are to 1) refine and validate appropriate quantitative COMs and biomarkers and 2) conduct a multi-site clinical trial readiness study to ensure that they can be successfully implemented. We will test the hypothesis that CDD specific COMs can be refined to accurately and reproducibly track meaningful changes in clinical trials: Aim 1: Generate and validate a suite of COMs and biomarkers necessary to comprehensively assess disease modification in CDD. Aim 2: Conduct a multi-site clinical trial readiness study to assess implementation, longitudinal stability, and collect baseline COMs and EEG/evoked potential data. Overall Impact: These outcome measures will establish clinical trial readiness for CDD and generate historic baseline outcome data, ensuring optimal testing of potential new therapeutics including gene therapy. Furthermore, these measures will be adaptable to other DEEs by enabling choices of outcome measures beyond existing NINDS supported measurement tools (NeuroQoL, PROMIS, Toolbox) that are not designed for the severity of the DEE populations.

Official Title
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Multi-Site Validation of Biomarkers and Core Clinical Outcome Measures for Clinical Trials Readiness in CDKL5 Deficiency Disorder

Conditions
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CDKL5, CDKL5 Deficiency Disorder, CDD

Intervention / Treatment
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* Other: No intervention.


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All children diagnosed with CDD age 1-month to 100 years of age that are receiving care at one of the study institutions or are registered with the International CDKL5 Disorder Database will be considered for the study population. Exclusion Criteria: Individuals who do not meet study inclusion criteria.

Ages Eligible for Study
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Minimum Age: 1 Month
Maximum Age: 100 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: No intervention.|No intervention administered as part of this study; observational only.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| CDKL5 Deficiency Disorder (CDD) Clinical Severity Assessment - Clinician (CCSA-Clinician) | Measured by clinician rating of patient. Item scores are transformed to a scale of 0-100 and the total score is calculated as a mean item score. Higher scores indicate higher severity. | 5 years | 
| CDKL5 Deficiency Disorder (CDD) Clinical Severity Assessment - Caregiver (CCSA-Caregiver) | Measured by caregiver/parent rating of patient on a scale of 0-100 with a higher score indicating higher severity. | 5 years | 
| CDKL5 Deficiency Disorder (CDD) Development Questionnaire - Caregiver (CDQ-Caregiver) | Measured by caregiver/parent rating of patient on a scale of 0-100 with a higher score indicating higher severity. | 5 years | 
| Communication and Symbolic Behavior Scales - Developmental Profile Infant Toddler Checklist (CSBS-DP ITC) | Measured by caregiver/parent rating of patient on a 24-item questionnaire. Three composite scores and a total score can be derived. Items contribute to the 0-57 point scale for the total score with lower scores indicating concerns for communication skills. | 5 years | 
| Sleep Disorder Scale for Children (SDSC) | Measured by caregiver/parent rating of patient on a 26- Likert type item questionnaire. Scale goes from 0-39 with a higher score indicating higher severity of sleep disorder. Each subscale is scored through the summation of all the subscale items. Comparing scores were the normative data reported in the initial validation paper, z-scores and t-scores can be derived. The t-score enables scores to be dichotomized as within normal range or outside of normal range, compared to the general population. | 5 years | 
| Quality of Life Inventory - Disability (QI-Disability) | This is a quality of life measure for children with intellectual disability. The measure comprises 32 items that are rated on a five-point Likert scale and group into six subscales: physical health, positive emotions, negative emotions, social interactions, independence, and leisure and outdoors. Following transformation to a 100-point scale, item scores in each subscale are summed and divided by the number of items to give a subscale score. The mean of the six subscale scores is calculated to give the total QOL score. | 5 years | 
| CDKL5 Deficiency Disorder (CDD) Gross Motor (CDD-Motor) | This is a video measure of gross motor function, based on the Rett Syndrome Gross Motor Scale with additional items that enable measurement of head control and sitting. Parents are provided with a filming protocol, video clips are uploaded to the investigators, and data are coded according to a predetermined coding system. | 5 years | 
| CDKL5 Deficiency Disorder (CDD) Fine Motor (CDD-Hand) | This is a video measure of fine motor function based on the Rett Syndrome Hand Function Scale with additional instructions on filming for if the patient has Cortical Visual Impairment. Parents are provided with a filming protocol, video clips are uploaded to the investigators, and data are coded according to a predetermined coding system. | 5 years | 
| Electroencephalogram/Evoked Potentials (EEG/EP) characteristics in CDKL5 Deficiency Disorder. | Measured by correlations of EEG/EP with other study scales. | 5 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Frequency of different mutations in the CDKL5 Deficiency Disorder population | Measured by information obtained from genetic reports of enrolled participants. | 5 years | 
| Frequency of medications and their indications in the CDKL5 Deficiency Disorder population | Measured by medication/indication data obtained from medical record review and/or caregiver report. | 5 years | 
| Social Determinants of Health (SDOH) in CDKL5 Deficiency Disorder population | Measured by data elements that are collected to describe the socioeconomic status of the study population. Examples include caregiver education level, marital status and employment status, patient living situation, household income, and primary caregiver information. | 5 years |