Back to resultsLong-Term Safety Study of Retigabine Immediate Release (IR) as Adjunctive Therapy in the Treatment of Adults With Partial-Onset Seizures (POS) (IR)
Primary Purpose
Epilepsy
Status
Completed
Phase
Phase 3
Locations
International
Study Type
Interventional
Intervention
Retigabine IR
Sponsored by
About this trial
This is an interventional treatment trial for Epilepsy focused on measuring Partial-onset seizures, retigabine IR, Open Label Extension, GW582892, Epilepsy
Eligibility Criteria
Inclusion Criteria:
- The subject has successfully completed the 20-weeks (4-weeks Titration and 16-weeks of Flexible Dose Evaluation Phases) of treatment with retigabine IR as adjunctive therapy to one of the pre-specified AEDs in the parent study RGB113905.
- The investigator and the subject, or caregiver, if applicable, should consider it beneficial for the subject to receive continued retigabine IR therapy.
- The subject is able and willing to maintain an accurate and complete daily written Seizure Calendar or has a caregiver who is able and willing to maintain an accurate and complete daily written Seizure Calendar for the entire duration of the study.
- The subject has given written informed consent, or has a legally authorized representative who has given written informed consent, prior to the performance of any study assessments.
- A female subject is eligible to enter and participate in the study if she is of non-childbearing potential (i.e., physiologically incapable of becoming pregnant, including any female who is pre- menarcheal or post menopausal).
- A female subject is eligible to enter and participate in the study if she is child-bearing potential and has a negative pregnancy test at Screening, and agrees to use one of the contraceptive methods listed in Appendix 3 of the protocol.
- A female subject is eligible to enter and participate in the study if she not pregnant or lactating or planning to become pregnant during the study.
- French subjects only: In France, a subject will be eligible for inclusion in this study only if either affiliated to or a beneficiary of a social security category.
Exclusion Criteria:
- Has met any of the withdrawal criteria in the previous RGB113905 study or has clinically significant abnormal clinical laboratory or ECG findings not resolved prior to entry to the open-label extension study.
- Is suffering from acute or progressive neurological disease, severe psychiatric disease, or severe mental abnormalities that are likely to interfere with the study objectives.
- Has any medical condition that, in the investigator's judgment, is considered to be clinically significant and could potentially affect subject safety or study outcome, including but not limited to: clinically significant cardiac, renal, hepatic condition, or a condition that affects the absorption, distribution, metabolism or excretion of drugs.
- Has any abnormality on 12-lead ECG at Screening which is clinically significant in the opinion of the investigator, or has QTc (either QTcB Bazett's correction or QTcF Fridericia's correction) >500 msec or >530 msec for subjects with Bundle Branch Block or an increase in QTc of >60 msec from Baseline in the parent study.
- Is unwilling or inability to follow the study procedures or reporting of AEs.
- Is planning on following a ketogenic diet or planning surgery or implantation of a Vagus Nerve Stimulator (VNS) to control seizures during the study. Note: Subjects who already have a VNS implanted which is functional may be permitted to enter the study.
- Has active suicidal plan/intent or has had active suicidal thoughts in the past 6 months. Has history of suicide attempt in the last 2 years or more than 1 lifetime suicide attempt.
Sites / Locations
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
- GSK Investigational Site
Arms of the Study
Arm 1
Arm Type
Experimental
Arm Label
Retigabine IR
Arm Description
Open label flexible dose between 300 mg/day (Minimum) and 1200 mg/day (maximum).
Outcomes
Primary Outcome Measures
Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Serious AEs (TESAEs): Safety Population
An AE is any untoward medical occurrence in a clinical investigation participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. SAE is defined as any untoward medical occurrence that, at any dose results in death, is life-threatening, requires hospitalization or prolongation of existing hospitalization, results in disability, is a congenital anomaly/ birth defect or is associated with liver injury or impaired liver function. TEAE refers to an AE for which the onset was on or after the date of the first retigabine dose in this study and on or before 30 days after the last retigabine dose date. AEs that started in the parent study that increased in severity during this study were also considered treatment-emergent. The analysis was performed on Safety Population, which included participants who took at least one dose of study medication after they had enrolled into this OLE study.
Number of Participants With AEs and SAEs: All SFUCP Subjects
An AE is any untoward medical occurrence in a clinical investigation participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. SAE is defined as any untoward medical occurrence that, at any dose results in death, is life-threatening, requires hospitalization or prolongation of existing hospitalization, results in disability, is a congenital anomaly/ birth defect or is associated with liver injury or impaired liver function. The following AEs were collected in the SFUCP: AEs related to the finding(s) of pigmentation/, discoloration of the eye/skin, AEs related to unexplained vision loss, SAEs, Deaths and Pregnancies. SFUCP collected AEs are those for which onset was 31 days or more after the last dose of retigabine. The analysis was performed on the All SFUCP Subjects population which comprised of all subjects who enter the SFUCP.
Number of Participants Withdrawn Due to TEAEs
An AE is any untoward medical occurrence in a clinical investigation participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. SAE is any untoward medical occurrence that, at any dose results in death, is life-threatening, requires hospitalization or prolonged existing hospitalization, results in disability, is a congenital anomaly/birth defect or is associated with liver injury or impaired liver function. TEAE refers to an AE for which the onset was on or after the date of the first retigabine dose and on or before 30 days after the last retigabine dose date.
Number of Participants With Retinal Pigmentary Abnormalities
Number of participants with abnormal findings after eye examination were evaluated. Only retinal pigmentary abnormalities detected on-treatment with retigabine were presented. Retinal pigmentary abnormalities included abnormalities in the macula, peripheral retina and unspecified location.
Number of Participants With Pigmentation of Non-retinal Ocular Tissue(s)
Number of participants with abnormal findings after eye examination were evaluated. Pigmentation of non-retinal ocular tissue (s) detected on-treatment with retigabine were presented. Non-retinal pigmentary abnormalities included abnormalities in the sclera and/ or conjunctiva, cornea, iris and lens.
Number of Participants With Abnormal Discoloration of Skin
Number of participants with Dermatologist-Confirmed abnormal discoloration of skin including skin around the eyes and eyelids, lips, nails, or mucosa were evaluated. Only abnormalities occurring on-treatment with retigabine were presented.
Number of Participants With a Clinically Significant Decrease in Visual Acuity From Initial Examination
Number of participants with a clinically significant decrease in visual acuity from initial examination were evaluated. Only abnormalities occurring on-treatment with retigabine were presented.
Number of Participants With Decrease in Confrontational Visual Field From Initial Examination
Number of participants with a clinically significant decrease in confrontational visual field from initial examination were evaluated. Only abnormalities occurring on-treatment with retigabine were presented.
Number of Participants With Potential Clinical Concern (PCC) Values of Change From Baseline in Vital Signs and Weight
Vital signs including systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) were measured after at least 5 minutes of rest. Body weight was measured without shoes and wearing light clothing. Baseline assessments in this OLE study were defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was calculated by subtracting the Baseline value from the post-baseline value. Increase or decrease of >=20 in SBP, increase or decrease of >=15 in DBP and HR were considered as PCC values. Number of participants with PCC values of vital signs for any visit post-Baseline are presented.
Change From Baseline in Electrocardiogram (ECG) Parameter Including HR
Single measurements of 12-lead ECG were obtained in supine position after at least 10 minutes of rest using an ECG machine to measure HR. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Change From Baseline in ECG Parameter Including PR Interval, QRS Duration, Uncorrected QT Interval, Corrected QT by Bazett's Formula (QTcB), Corrected QT by Fridericia's Formula (QTcF) and RR Interval
Single measurements of 12-lead ECG were obtained in supine position after at least 10 minutes of rest using an ECG machine to measure parameters including PR interval, QRS duration, uncorrected QT interval, QTcB, QTcF and RR interval. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Number of Participants With Clinical Chemistry Parameters of PCC
Number of participants with chemistry parameters of PCC at 'any visit post-Baseline' are presented. Chemistry parameters for which PCC values were identified were alanine aminotransferase (ALT) (if value >=3 * upper limit of normal [ULN]), alkaline phosphatase (alk.phosphatase) (if value >=3*ULN), aspartate aminotransferase (AST) (if value >=3*ULN), calcium (if value <=1.8962 or >=2.8692), carbon-di-oxide (CO2) (if value <=18 or >=36), chloride (if value <=92 or >=112), creatine kinase (if value >=3*ULN), direct bilirubin (if value >=1.5*ULN), glucose (if value <=2.7755 or >=11.102), lactate dehydrogenase (LD) (if value >=3*ULN), magnesium (if value <0.36 or >2.50), potassium (if value <=3.0 or >=6.0), sodium (if value <=127 or >=153), total bilirubin (if value >=1.5*ULN), total protein (if value <45 or >100), blood urea nitrogen (BUN) (if value >=14.28). Only those participants with data available at specific time points were analyzed (represented by n=X in the category titles).
Number of Participants With Hematology Parameters of PCC
Blood samples were collected from participants to evaluate hematology parameters. Number of participants with clinical hematology parameters of PCC at 'any visit post-Baseline' are presented. Hematology parameters for which PCC values were identified were eosinophils (if value is >0.8), hematocrit (if value is <=0.32 for males and <=0.28 for females), platelet count (if value is <=100 or >=550), total neutrophils (if value is <=1.8), white blood cells (WBC) (if value is <=2.8 or >=16). Only those participants with data available at specific time points were analyzed (represented by n=X in the category titles).
Number of Participants With Urinalysis Parameters of PCC
Urine samples were collected from participants at specific time points. Number of participants with urinalysis parameters of PCC at 'any visit post-Baseline' are presented. Urinalysis parameters for which PCC values were identified were albumin/creatinine ratio (if value is >11.3), red blood cells (RBC) (if value is 3-5 or higher), WBC (if value is 5-10 or higher for male and 10-15 or higher for females), specific gravity (if value is <1.001 or >1.035) and potential of hydrogen (pH) (if value is <4.6 or >8.0). Only those participants with data available at specific time points were analyzed (represented by n=X in the category titles).
Change From Baseline in Albumin and Total Protein
Blood samples were collected from participants for evaluation of change from Baseline in clinical chemistry parameters including albumin and total protein. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Change From Baseline in Alk. Phosphatase, ALT, AST, Creatine Kinase and LD Levels
Blood samples were collected from participants for evaluation of change from Baseline in clinical chemistry parameters including alk. phosphatase, ALT, AST, creatine kinase and LD. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Change From Baseline in Direct Bilirubin, Total Bilirubin and Creatinine
Blood samples were collected from participants for evaluation of change from Baseline in clinical chemistry parameters including direct bilirubin, total bilirubin and creatinine. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Change From Baseline in BUN/Creatinine Ratio
Blood samples were collected from participants for evaluation of change from Baseline in clinical chemistry parameters including BUN/creatinine ratio. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Change From Baseline in Calcium, Chloride, CO2, Glucose, Potassium, Magnesium, Sodium and BUN
Blood samples were collected from participants for evaluation of change from Baseline in clinical chemistry parameters including calcium, chloride, CO2, glucose, potassium, magnesium, sodium and BUN. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Change From Baseline in Absolute Basophils, Absolute Eosinophils, Absolute Lymphocytes, Absolute Monocytes, Absolute Total Neutrophils, Platelet Count and WBC Count
Blood samples were collected from participants for evaluation of change from Baseline in clinical hematology parameters including absolute basophils, eosinophils, lymphocytes, monocytes, neutrophils, platelet count and WBC count. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Change From Baseline in Hemoglobin and Mean Corpuscle Hemoglobin Concentration (MCHC) Levels
Blood samples were collected from participants for evaluation of change from Baseline in clinical hematology parameters including hemoglobin and MCHC. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Change From Baseline in Hematocrit Levels
Blood samples were collected from participants for evaluation of change from Baseline in clinical hematology parameters including hematocrit. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Change From Baseline in Mean Corpuscle Hemoglobin (MCH) Levels
Blood samples were collected from participants for evaluation of change from Baseline in clinical hematology parameters including MCH. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Change From Baseline in Mean Corpuscle Volume (MCV) and Mean Platelet Volume (MPV) Levels
Blood samples were collected from participants for evaluation of change from Baseline in clinical hematology parameters including MCV and MPV. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Change From Baseline in RBC Count
Blood samples were collected from participants for evaluation of change from Baseline in clinical hematology parameters including RBC count. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Change From Baseline in Percent Basophils, Percent Eosinophils, Percent Lymphocytes, Percent Monocytes, Percent Neutrophils and RBC Distribution Width (RDW) Levels
Blood samples were collected from participants for evaluation of change from Baseline in clinical hematology parameters including percent basophils, eosinophils, lymphocytes, monocytes, neutrophils and RDW. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Change From Baseline in Urine Albumin Creatinine Ratio
Urine samples were collected from participants for evaluation of change from Baseline in urinalysis parameters including albumin creatinine ratio. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Change From Baseline in Urine Albumin Levels
Urine samples were collected from participants for evaluation of change from Baseline in urinalysis parameters including albumin levels. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Change From Baseline in Urine Creatinine Levels
Urine samples were collected from participants for evaluation of change from Baseline in urinalysis parameters including creatinine levels. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Changes From Baseline in American Urological Association Symptom Scale (AUA SS) Score
The effect of retigabine on bladder function was assessed using AUA symptom index. It is a 7-item Likert-scored scale ranging from 0 (no symptom at all) to 5 (almost always symptoms present) with a total possible score of 35. AUA SS score is the sum of the responses to these seven questions. The total score for all questions was classified as mild (0 to 7), moderate (8 to 19), or severe (>19). Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Change From Baseline in Post-Void Residual (PVR) Bladder Ultrasound Urine Volume
The PVR bladder ultrasound was used to assess urinary retention. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Number of Participants With Suicidal Ideation or Behavior Assessed by the Columbia Suicide Severity Rating Scale (C-SSRS) Score
Number of participants with suicidal ideation or behavior during treatment were assessed using the C-SSRS score scale. It is a brief questionnaire designed to assess severity and change in suicidality by integrating both behavior and ideation using a semi-structured interview to probe participant responses. Participants are classified with respect to extent of suicidal ideation, extent of suicidal behavior, and with respect to self-injurious behavior.
Number of Participants Experiencing New Seizure Types
Number of participants experiencing new seizure type that is seizure not experienced before were summarized. New seizure types were classified into 5 classes including type A (simple partial seizure), type B (complex partial seizure), type C (Partials, evolving to Secondary Generalized Seizures), type D (Generalized, excluding Myoclonic Seizures), type D2 (Myoclonic Seizures) and type E (Unclassified Seizures).
Number of Participants Experiencing Worsening of Seizures
Worsening of seizures was defined as an increase in seizure frequency or the occurrence of a new, more severe seizure type, or status epilepticus occurring in a participant without a history of status epilepticus. An increase in seizure frequency was defined as doubling of the 28-day seizure frequency compared to the 28-day Baseline seizure frequency established in the parent study. Number of participants experiencing worsening of seizure during study period are presented.
Duration of Retigabine Exposure
Duration of exposure was calculated from the first dose through the last dose during study including the Taper Phase and presented using median and full range.
Number of Participants With Resolution of Abnormal Eye Pigmentation After Discontinuation of Retigabine
The ophthalmologist/retina specialist determined the presence or absence of retinal and non-retinal ocular abnormalities. Retinal abnormalities included abnormalities in the macula and/or the peripheral retina and non-retinal ocular pigmentary abnormality.
Number of Participants With Resolution of Dermatologist Confirmed Abnormal Discoloration After Discontinuation of Retigabine
Participants who enter the SFUCP who had an on-treatment finding(s) of abnormal discoloration of skin, lips, nails or mucosa confirmed by a dermatologist entered the SFUCP and underwent assessments performed by a dermatologist at 6-monthly intervals. The assessment of the participant's skin included assessment of the skin around the eyes and the eyelids, lips, nails, and mucosa.
Time From Discontinuation of Retigabine to Resolution of Abnormal Eye Pigmentation
Retinal pigmentary abnormality was determined by either an ophthalmologist or retina specialist. Retinal pigmentary abnormality included abnormality of macula, peripheral retina and unspecified location. If a participant had pigmentary abnormality of macula and pigmentary abnormality of the peripheral retina both should be resolved in order for retinal pigmentary abnormality to be considered resolved. If a participant had non-retinal ocular pigmentary abnormality in more than one location (conjunctiva, sclera, cornea, iris or lens), all should be resolved for non-retinal pigmentary abnormality to be considered resolved.
Time From Discontinuation of Retigabine to Resolution of All Dermatologist-confirmed Abnormal Discoloration
Assessments were at approximately 6-monthly intervals (timed relative to the participants previous dermatology assessment) until the abnormal discoloration either resolved or stabilized (as defined by no changes over 2 consecutive 6-monthly assessments performed by the dermatologist over at least 12 months after discontinuation of retigabine). The assessment of the participant's skin included assessment of the skin around the eyes and the eyelids, lips, nails, and mucosa. Only participants with resolution of the specified tissue are included in this analysis.
Secondary Outcome Measures
Number of Participants Experiencing a 0 to <25, 25 to <50, 50 to <75 and 75 to 100 Percent Reduction in 28 Day POS Frequency From Baseline
The seizure frequency was recorded in daily seizure calendar by participants during the treatment period. Baseline assessments in this OLE study are defined by and taken directly from the Baseline assessments in the parent study NCT01336621.
Percent Change From Baseline in 28-day Partial-onset Seizure Frequency
The seizure frequency was recorded in daily seizure calendar by participants during the treatment period. Percent change from Baseline in 28-day partial onset seizure frequency was presented as mean and standard deviation (SD). Baseline assessments in this OLE study are defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Percent change from Baseline was calculated as post-Baseline value minus Baseline value divided by Baseline value into 100.
Number of Participants Experiencing an Increase in 28-day Partial-onset Seizure Frequency From Baseline
The seizure frequency was recorded in daily seizure calendar by participants during the treatment period. Baseline assessments in this OLE study are defined by and taken directly from the Baseline assessments in the parent study NCT01336621.
Number of Participants Who Remained Seizure-free
The seizure frequency was recorded in daily seizure calendar by participants during the treatment period. Number of participants who were treated retigabine for at least 6 months and who remained seizure free for any 6 continuous months as well as number of participants who were treated with retigabine for at least 12 months and who remained seizure free for any 12 continuous months are presented.
Full Information
1. Study Identification
Unique Protocol Identification Number
NCT01336621
Brief Title
Long-Term Safety Study of Retigabine Immediate Release (IR) as Adjunctive Therapy in the Treatment of Adults With Partial-Onset Seizures (POS)
Acronym
IR
Official Title
A Multicentre, Open-Label, Long-Term, Safety and Tolerability Study of Retigabine Immediate Release (IR) in Adults With Partial-Onset Seizures (Extension of Study RGB113905)
Study Type
Interventional
2. Study Status
Record Verification Date
March 2020
Overall Recruitment Status
Completed
Study Start Date
February 21, 2011 (Actual)
Primary Completion Date
December 14, 2016 (Actual)
Study Completion Date
September 13, 2017 (Actual)
3. Sponsor/Collaborators
Responsible Party, by Official Title
Sponsor
Name of the Sponsor
GlaxoSmithKline
4. Oversight
Studies a U.S. FDA-regulated Drug Product
Yes
Studies a U.S. FDA-regulated Device Product
No
Product Manufactured in and Exported from the U.S.
Yes
Data Monitoring Committee
No
5. Study Description
Brief Summary
The purpose of this Phase III study is to assess the long-term safety, tolerability and efficacy of flexibly dosed retigabine Immediate Release (IR) as adjunctive therapy in adult subjects with partial-onset seizures. In addition, those subjects who successfully completed 20 weeks of adjunctive treatment with retigabine IR in the parent study, RGB113905, and who were thought to have benefitted from treatment will be provided continued access to retigabine IR.
Detailed Description
RTG113413 is an open-label, multicentre extension study of RGB113905. This study will enroll adult subjects with partial-onset seizures (POS) who successfully completed 20 weeks of adjunctive treatment with retigabine IR (4-weeks Titration Phase and 16-weeks Flexible Dose Evaluation Phase) in the parent study, RGB113905 and who were thought to have benefitted from the treatment.
The Screening Visit (Visit 1) will be performed on the same day as the final visit of the parent study (Visit 7/Week 20). Subjects entering the extension study will initially receive the same dose of retigabine IR and concurrent antiepileptic drug (AED) as they were receiving on the final visit of the parent study. After the first week of the extension study, the subject's retigabine dose can be adjusted based on efficacy and tolerability. The overall daily dose of retigabine IR must be maintained between 300 mg/day (minimum) and 1200 mg/day (maximum). In addition, the dose and the number of concurrent AEDs can be adjusted to meet the individual needs of the subject. Retigabine IR monotherapy is not permitted. If concurrent AED therapy is removed, the subject must be withdrawn from the study.
Subjects in this study will be eligible to receive retigabine IR treatment until one of the following criteria have been met: 1) regulatory approval and commercial availability of retigabine IR or 2) retigabine IR is not approved by the regulatory authorities or 3) the study is terminated by the sponsor for reasons including, but not limited to, safety issues or 4) subject is withdrawn or withdraws consent or 5) subject has received retigabine IR treatment for a total of 3 years and options i-iv have not been met. After the Screening Visit, subjects will be required to attend 4 further clinic visits at Weeks 13, 26, 39, and 52 in the first year of the study and a total of 3 clinic visits at approximately 4-monthly intervals during each of the second and third year of study. Upon completion or early withdrawal, subjects will begin a 3-week taper period and then return for a follow-up visit.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Epilepsy
Keywords
Partial-onset seizures, retigabine IR, Open Label Extension, GW582892, Epilepsy
7. Study Design
Primary Purpose
Treatment
Study Phase
Phase 3
Interventional Study Model
Single Group Assignment
Masking
None (Open Label)
Allocation
N/A
Enrollment
98 (Actual)
8. Arms, Groups, and Interventions
Arm Title
Retigabine IR
Arm Type
Experimental
Arm Description
Open label flexible dose between 300 mg/day (Minimum) and 1200 mg/day (maximum).
Intervention Type
Drug
Intervention Name(s)
Retigabine IR
Intervention Description
Flexible dose between 300 mg/day (minimum) and 1200 mg/day (maximum)
Primary Outcome Measure Information:
Title
Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Serious AEs (TESAEs): Safety Population
Description
An AE is any untoward medical occurrence in a clinical investigation participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. SAE is defined as any untoward medical occurrence that, at any dose results in death, is life-threatening, requires hospitalization or prolongation of existing hospitalization, results in disability, is a congenital anomaly/ birth defect or is associated with liver injury or impaired liver function. TEAE refers to an AE for which the onset was on or after the date of the first retigabine dose in this study and on or before 30 days after the last retigabine dose date. AEs that started in the parent study that increased in severity during this study were also considered treatment-emergent. The analysis was performed on Safety Population, which included participants who took at least one dose of study medication after they had enrolled into this OLE study.
Time Frame
Up to 5.8 years
Title
Number of Participants With AEs and SAEs: All SFUCP Subjects
Description
An AE is any untoward medical occurrence in a clinical investigation participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. SAE is defined as any untoward medical occurrence that, at any dose results in death, is life-threatening, requires hospitalization or prolongation of existing hospitalization, results in disability, is a congenital anomaly/ birth defect or is associated with liver injury or impaired liver function. The following AEs were collected in the SFUCP: AEs related to the finding(s) of pigmentation/, discoloration of the eye/skin, AEs related to unexplained vision loss, SAEs, Deaths and Pregnancies. SFUCP collected AEs are those for which onset was 31 days or more after the last dose of retigabine. The analysis was performed on the All SFUCP Subjects population which comprised of all subjects who enter the SFUCP.
Time Frame
Up to 2.6 years
Title
Number of Participants Withdrawn Due to TEAEs
Description
An AE is any untoward medical occurrence in a clinical investigation participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. SAE is any untoward medical occurrence that, at any dose results in death, is life-threatening, requires hospitalization or prolonged existing hospitalization, results in disability, is a congenital anomaly/birth defect or is associated with liver injury or impaired liver function. TEAE refers to an AE for which the onset was on or after the date of the first retigabine dose and on or before 30 days after the last retigabine dose date.
Time Frame
Up to 5.8 years
Title
Number of Participants With Retinal Pigmentary Abnormalities
Description
Number of participants with abnormal findings after eye examination were evaluated. Only retinal pigmentary abnormalities detected on-treatment with retigabine were presented. Retinal pigmentary abnormalities included abnormalities in the macula, peripheral retina and unspecified location.
Time Frame
Up to 5.8 years
Title
Number of Participants With Pigmentation of Non-retinal Ocular Tissue(s)
Description
Number of participants with abnormal findings after eye examination were evaluated. Pigmentation of non-retinal ocular tissue (s) detected on-treatment with retigabine were presented. Non-retinal pigmentary abnormalities included abnormalities in the sclera and/ or conjunctiva, cornea, iris and lens.
Time Frame
Up to 5.8 years
Title
Number of Participants With Abnormal Discoloration of Skin
Description
Number of participants with Dermatologist-Confirmed abnormal discoloration of skin including skin around the eyes and eyelids, lips, nails, or mucosa were evaluated. Only abnormalities occurring on-treatment with retigabine were presented.
Time Frame
Up to 5.8 years
Title
Number of Participants With a Clinically Significant Decrease in Visual Acuity From Initial Examination
Description
Number of participants with a clinically significant decrease in visual acuity from initial examination were evaluated. Only abnormalities occurring on-treatment with retigabine were presented.
Time Frame
Up to 5.8 years
Title
Number of Participants With Decrease in Confrontational Visual Field From Initial Examination
Description
Number of participants with a clinically significant decrease in confrontational visual field from initial examination were evaluated. Only abnormalities occurring on-treatment with retigabine were presented.
Time Frame
Up to 5.8 years
Title
Number of Participants With Potential Clinical Concern (PCC) Values of Change From Baseline in Vital Signs and Weight
Description
Vital signs including systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) were measured after at least 5 minutes of rest. Body weight was measured without shoes and wearing light clothing. Baseline assessments in this OLE study were defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was calculated by subtracting the Baseline value from the post-baseline value. Increase or decrease of >=20 in SBP, increase or decrease of >=15 in DBP and HR were considered as PCC values. Number of participants with PCC values of vital signs for any visit post-Baseline are presented.
Time Frame
Up to 5.8 years
Title
Change From Baseline in Electrocardiogram (ECG) Parameter Including HR
Description
Single measurements of 12-lead ECG were obtained in supine position after at least 10 minutes of rest using an ECG machine to measure HR. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Time Frame
Baseline and up to 5.8 years
Title
Change From Baseline in ECG Parameter Including PR Interval, QRS Duration, Uncorrected QT Interval, Corrected QT by Bazett's Formula (QTcB), Corrected QT by Fridericia's Formula (QTcF) and RR Interval
Description
Single measurements of 12-lead ECG were obtained in supine position after at least 10 minutes of rest using an ECG machine to measure parameters including PR interval, QRS duration, uncorrected QT interval, QTcB, QTcF and RR interval. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Time Frame
Baseline and up to 5.8 years
Title
Number of Participants With Clinical Chemistry Parameters of PCC
Description
Number of participants with chemistry parameters of PCC at 'any visit post-Baseline' are presented. Chemistry parameters for which PCC values were identified were alanine aminotransferase (ALT) (if value >=3 * upper limit of normal [ULN]), alkaline phosphatase (alk.phosphatase) (if value >=3*ULN), aspartate aminotransferase (AST) (if value >=3*ULN), calcium (if value <=1.8962 or >=2.8692), carbon-di-oxide (CO2) (if value <=18 or >=36), chloride (if value <=92 or >=112), creatine kinase (if value >=3*ULN), direct bilirubin (if value >=1.5*ULN), glucose (if value <=2.7755 or >=11.102), lactate dehydrogenase (LD) (if value >=3*ULN), magnesium (if value <0.36 or >2.50), potassium (if value <=3.0 or >=6.0), sodium (if value <=127 or >=153), total bilirubin (if value >=1.5*ULN), total protein (if value <45 or >100), blood urea nitrogen (BUN) (if value >=14.28). Only those participants with data available at specific time points were analyzed (represented by n=X in the category titles).
Time Frame
Up to 5.8 years
Title
Number of Participants With Hematology Parameters of PCC
Description
Blood samples were collected from participants to evaluate hematology parameters. Number of participants with clinical hematology parameters of PCC at 'any visit post-Baseline' are presented. Hematology parameters for which PCC values were identified were eosinophils (if value is >0.8), hematocrit (if value is <=0.32 for males and <=0.28 for females), platelet count (if value is <=100 or >=550), total neutrophils (if value is <=1.8), white blood cells (WBC) (if value is <=2.8 or >=16). Only those participants with data available at specific time points were analyzed (represented by n=X in the category titles).
Time Frame
Up to 5.8 years
Title
Number of Participants With Urinalysis Parameters of PCC
Description
Urine samples were collected from participants at specific time points. Number of participants with urinalysis parameters of PCC at 'any visit post-Baseline' are presented. Urinalysis parameters for which PCC values were identified were albumin/creatinine ratio (if value is >11.3), red blood cells (RBC) (if value is 3-5 or higher), WBC (if value is 5-10 or higher for male and 10-15 or higher for females), specific gravity (if value is <1.001 or >1.035) and potential of hydrogen (pH) (if value is <4.6 or >8.0). Only those participants with data available at specific time points were analyzed (represented by n=X in the category titles).
Time Frame
Up to 5.8 years
Title
Change From Baseline in Albumin and Total Protein
Description
Blood samples were collected from participants for evaluation of change from Baseline in clinical chemistry parameters including albumin and total protein. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Time Frame
Baseline and up to 5.8 years
Title
Change From Baseline in Alk. Phosphatase, ALT, AST, Creatine Kinase and LD Levels
Description
Blood samples were collected from participants for evaluation of change from Baseline in clinical chemistry parameters including alk. phosphatase, ALT, AST, creatine kinase and LD. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Time Frame
Baseline and up to 5.8 years
Title
Change From Baseline in Direct Bilirubin, Total Bilirubin and Creatinine
Description
Blood samples were collected from participants for evaluation of change from Baseline in clinical chemistry parameters including direct bilirubin, total bilirubin and creatinine. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Time Frame
Baseline and up to 5.8 years
Title
Change From Baseline in BUN/Creatinine Ratio
Description
Blood samples were collected from participants for evaluation of change from Baseline in clinical chemistry parameters including BUN/creatinine ratio. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Time Frame
Baseline and up to 5.8 years
Title
Change From Baseline in Calcium, Chloride, CO2, Glucose, Potassium, Magnesium, Sodium and BUN
Description
Blood samples were collected from participants for evaluation of change from Baseline in clinical chemistry parameters including calcium, chloride, CO2, glucose, potassium, magnesium, sodium and BUN. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Time Frame
Baseline and up to 5.8 years
Title
Change From Baseline in Absolute Basophils, Absolute Eosinophils, Absolute Lymphocytes, Absolute Monocytes, Absolute Total Neutrophils, Platelet Count and WBC Count
Description
Blood samples were collected from participants for evaluation of change from Baseline in clinical hematology parameters including absolute basophils, eosinophils, lymphocytes, monocytes, neutrophils, platelet count and WBC count. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Time Frame
Baseline and up to 5.8 years
Title
Change From Baseline in Hemoglobin and Mean Corpuscle Hemoglobin Concentration (MCHC) Levels
Description
Blood samples were collected from participants for evaluation of change from Baseline in clinical hematology parameters including hemoglobin and MCHC. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Time Frame
Baseline and up to 5.8 years
Title
Change From Baseline in Hematocrit Levels
Description
Blood samples were collected from participants for evaluation of change from Baseline in clinical hematology parameters including hematocrit. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Time Frame
Baseline and up to 5.8 years
Title
Change From Baseline in Mean Corpuscle Hemoglobin (MCH) Levels
Description
Blood samples were collected from participants for evaluation of change from Baseline in clinical hematology parameters including MCH. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Time Frame
Baseline and up to 5.8 years
Title
Change From Baseline in Mean Corpuscle Volume (MCV) and Mean Platelet Volume (MPV) Levels
Description
Blood samples were collected from participants for evaluation of change from Baseline in clinical hematology parameters including MCV and MPV. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Time Frame
Baseline and up to 5.8 years
Title
Change From Baseline in RBC Count
Description
Blood samples were collected from participants for evaluation of change from Baseline in clinical hematology parameters including RBC count. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Time Frame
Up to 5.8 years
Title
Change From Baseline in Percent Basophils, Percent Eosinophils, Percent Lymphocytes, Percent Monocytes, Percent Neutrophils and RBC Distribution Width (RDW) Levels
Description
Blood samples were collected from participants for evaluation of change from Baseline in clinical hematology parameters including percent basophils, eosinophils, lymphocytes, monocytes, neutrophils and RDW. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Time Frame
Baseline and up to 5.8 years
Title
Change From Baseline in Urine Albumin Creatinine Ratio
Description
Urine samples were collected from participants for evaluation of change from Baseline in urinalysis parameters including albumin creatinine ratio. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Time Frame
Baseline and up to 5.8 years
Title
Change From Baseline in Urine Albumin Levels
Description
Urine samples were collected from participants for evaluation of change from Baseline in urinalysis parameters including albumin levels. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Time Frame
Baseline and up to 5.8 years
Title
Change From Baseline in Urine Creatinine Levels
Description
Urine samples were collected from participants for evaluation of change from Baseline in urinalysis parameters including creatinine levels. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Time Frame
Baseline and up to 5.8 years
Title
Changes From Baseline in American Urological Association Symptom Scale (AUA SS) Score
Description
The effect of retigabine on bladder function was assessed using AUA symptom index. It is a 7-item Likert-scored scale ranging from 0 (no symptom at all) to 5 (almost always symptoms present) with a total possible score of 35. AUA SS score is the sum of the responses to these seven questions. The total score for all questions was classified as mild (0 to 7), moderate (8 to 19), or severe (>19). Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Time Frame
Baseline and up to 5.8 years
Title
Change From Baseline in Post-Void Residual (PVR) Bladder Ultrasound Urine Volume
Description
The PVR bladder ultrasound was used to assess urinary retention. Baseline was defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Change from Baseline was defined as post-Baseline value minus Baseline value. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).
Time Frame
Baseline and up to 5.8 years
Title
Number of Participants With Suicidal Ideation or Behavior Assessed by the Columbia Suicide Severity Rating Scale (C-SSRS) Score
Description
Number of participants with suicidal ideation or behavior during treatment were assessed using the C-SSRS score scale. It is a brief questionnaire designed to assess severity and change in suicidality by integrating both behavior and ideation using a semi-structured interview to probe participant responses. Participants are classified with respect to extent of suicidal ideation, extent of suicidal behavior, and with respect to self-injurious behavior.
Time Frame
Up to 5.8 years
Title
Number of Participants Experiencing New Seizure Types
Description
Number of participants experiencing new seizure type that is seizure not experienced before were summarized. New seizure types were classified into 5 classes including type A (simple partial seizure), type B (complex partial seizure), type C (Partials, evolving to Secondary Generalized Seizures), type D (Generalized, excluding Myoclonic Seizures), type D2 (Myoclonic Seizures) and type E (Unclassified Seizures).
Time Frame
Up to 5.8 years
Title
Number of Participants Experiencing Worsening of Seizures
Description
Worsening of seizures was defined as an increase in seizure frequency or the occurrence of a new, more severe seizure type, or status epilepticus occurring in a participant without a history of status epilepticus. An increase in seizure frequency was defined as doubling of the 28-day seizure frequency compared to the 28-day Baseline seizure frequency established in the parent study. Number of participants experiencing worsening of seizure during study period are presented.
Time Frame
Up to 5.8 years
Title
Duration of Retigabine Exposure
Description
Duration of exposure was calculated from the first dose through the last dose during study including the Taper Phase and presented using median and full range.
Time Frame
Up to 5.8 years
Title
Number of Participants With Resolution of Abnormal Eye Pigmentation After Discontinuation of Retigabine
Description
The ophthalmologist/retina specialist determined the presence or absence of retinal and non-retinal ocular abnormalities. Retinal abnormalities included abnormalities in the macula and/or the peripheral retina and non-retinal ocular pigmentary abnormality.
Time Frame
Up to 2.6 years
Title
Number of Participants With Resolution of Dermatologist Confirmed Abnormal Discoloration After Discontinuation of Retigabine
Description
Participants who enter the SFUCP who had an on-treatment finding(s) of abnormal discoloration of skin, lips, nails or mucosa confirmed by a dermatologist entered the SFUCP and underwent assessments performed by a dermatologist at 6-monthly intervals. The assessment of the participant's skin included assessment of the skin around the eyes and the eyelids, lips, nails, and mucosa.
Time Frame
Up to 2.6 years
Title
Time From Discontinuation of Retigabine to Resolution of Abnormal Eye Pigmentation
Description
Retinal pigmentary abnormality was determined by either an ophthalmologist or retina specialist. Retinal pigmentary abnormality included abnormality of macula, peripheral retina and unspecified location. If a participant had pigmentary abnormality of macula and pigmentary abnormality of the peripheral retina both should be resolved in order for retinal pigmentary abnormality to be considered resolved. If a participant had non-retinal ocular pigmentary abnormality in more than one location (conjunctiva, sclera, cornea, iris or lens), all should be resolved for non-retinal pigmentary abnormality to be considered resolved.
Time Frame
Up to 2.6 years
Title
Time From Discontinuation of Retigabine to Resolution of All Dermatologist-confirmed Abnormal Discoloration
Description
Assessments were at approximately 6-monthly intervals (timed relative to the participants previous dermatology assessment) until the abnormal discoloration either resolved or stabilized (as defined by no changes over 2 consecutive 6-monthly assessments performed by the dermatologist over at least 12 months after discontinuation of retigabine). The assessment of the participant's skin included assessment of the skin around the eyes and the eyelids, lips, nails, and mucosa. Only participants with resolution of the specified tissue are included in this analysis.
Time Frame
Up to 2.6 years
Secondary Outcome Measure Information:
Title
Number of Participants Experiencing a 0 to <25, 25 to <50, 50 to <75 and 75 to 100 Percent Reduction in 28 Day POS Frequency From Baseline
Description
The seizure frequency was recorded in daily seizure calendar by participants during the treatment period. Baseline assessments in this OLE study are defined by and taken directly from the Baseline assessments in the parent study NCT01336621.
Time Frame
Baseline and up to 5.8 years
Title
Percent Change From Baseline in 28-day Partial-onset Seizure Frequency
Description
The seizure frequency was recorded in daily seizure calendar by participants during the treatment period. Percent change from Baseline in 28-day partial onset seizure frequency was presented as mean and standard deviation (SD). Baseline assessments in this OLE study are defined by and taken directly from the Baseline assessments in the parent study NCT01336621. Percent change from Baseline was calculated as post-Baseline value minus Baseline value divided by Baseline value into 100.
Time Frame
Baseline and up to 5.8 years
Title
Number of Participants Experiencing an Increase in 28-day Partial-onset Seizure Frequency From Baseline
Description
The seizure frequency was recorded in daily seizure calendar by participants during the treatment period. Baseline assessments in this OLE study are defined by and taken directly from the Baseline assessments in the parent study NCT01336621.
Time Frame
Baseline and up to 5.8 years
Title
Number of Participants Who Remained Seizure-free
Description
The seizure frequency was recorded in daily seizure calendar by participants during the treatment period. Number of participants who were treated retigabine for at least 6 months and who remained seizure free for any 6 continuous months as well as number of participants who were treated with retigabine for at least 12 months and who remained seizure free for any 12 continuous months are presented.
Time Frame
Up to 5.8 years
10. Eligibility
Sex
All
Minimum Age & Unit of Time
18 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria:
The subject has successfully completed the 20-weeks (4-weeks Titration and 16-weeks of Flexible Dose Evaluation Phases) of treatment with retigabine IR as adjunctive therapy to one of the pre-specified AEDs in the parent study RGB113905.
The investigator and the subject, or caregiver, if applicable, should consider it beneficial for the subject to receive continued retigabine IR therapy.
The subject is able and willing to maintain an accurate and complete daily written Seizure Calendar or has a caregiver who is able and willing to maintain an accurate and complete daily written Seizure Calendar for the entire duration of the study.
The subject has given written informed consent, or has a legally authorized representative who has given written informed consent, prior to the performance of any study assessments.
A female subject is eligible to enter and participate in the study if she is of non-childbearing potential (i.e., physiologically incapable of becoming pregnant, including any female who is pre- menarcheal or post menopausal).
A female subject is eligible to enter and participate in the study if she is child-bearing potential and has a negative pregnancy test at Screening, and agrees to use one of the contraceptive methods listed in Appendix 3 of the protocol.
A female subject is eligible to enter and participate in the study if she not pregnant or lactating or planning to become pregnant during the study.
French subjects only: In France, a subject will be eligible for inclusion in this study only if either affiliated to or a beneficiary of a social security category.
Exclusion Criteria:
Has met any of the withdrawal criteria in the previous RGB113905 study or has clinically significant abnormal clinical laboratory or ECG findings not resolved prior to entry to the open-label extension study.
Is suffering from acute or progressive neurological disease, severe psychiatric disease, or severe mental abnormalities that are likely to interfere with the study objectives.
Has any medical condition that, in the investigator's judgment, is considered to be clinically significant and could potentially affect subject safety or study outcome, including but not limited to: clinically significant cardiac, renal, hepatic condition, or a condition that affects the absorption, distribution, metabolism or excretion of drugs.
Has any abnormality on 12-lead ECG at Screening which is clinically significant in the opinion of the investigator, or has QTc (either QTcB Bazett's correction or QTcF Fridericia's correction) >500 msec or >530 msec for subjects with Bundle Branch Block or an increase in QTc of >60 msec from Baseline in the parent study.
Is unwilling or inability to follow the study procedures or reporting of AEs.
Is planning on following a ketogenic diet or planning surgery or implantation of a Vagus Nerve Stimulator (VNS) to control seizures during the study. Note: Subjects who already have a VNS implanted which is functional may be permitted to enter the study.
Has active suicidal plan/intent or has had active suicidal thoughts in the past 6 months. Has history of suicide attempt in the last 2 years or more than 1 lifetime suicide attempt.
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
GSK Clinical Trials
Organizational Affiliation
GlaxoSmithKline
Official's Role
Study Director
Facility Information:
Facility Name
GSK Investigational Site
City
Gent
ZIP/Postal Code
9000
Country
Belgium
Facility Name
GSK Investigational Site
City
Plovdiv
ZIP/Postal Code
4000
Country
Bulgaria
Facility Name
GSK Investigational Site
City
Sofia
ZIP/Postal Code
1113
Country
Bulgaria
Facility Name
GSK Investigational Site
City
Sofia
ZIP/Postal Code
1431
Country
Bulgaria
Facility Name
GSK Investigational Site
City
Limoges
ZIP/Postal Code
87042
Country
France
Facility Name
GSK Investigational Site
City
Strasbourg Cedex
ZIP/Postal Code
67098
Country
France
Facility Name
GSK Investigational Site
City
Bielefeld
State/Province
Nordrhein-Westfalen
ZIP/Postal Code
33617
Country
Germany
Facility Name
GSK Investigational Site
City
Bologna
State/Province
Emilia-Romagna
ZIP/Postal Code
40139
Country
Italy
Facility Name
GSK Investigational Site
City
Roma
State/Province
Lazio
ZIP/Postal Code
00163
Country
Italy
Facility Name
GSK Investigational Site
City
Roma
State/Province
Lazio
ZIP/Postal Code
00185
Country
Italy
Facility Name
GSK Investigational Site
City
Genova
State/Province
Liguria
ZIP/Postal Code
16153
Country
Italy
Facility Name
GSK Investigational Site
City
Torrette Di Ancona
State/Province
Marche
ZIP/Postal Code
60126
Country
Italy
Facility Name
GSK Investigational Site
City
Foggia
State/Province
Puglia
ZIP/Postal Code
71100
Country
Italy
Facility Name
GSK Investigational Site
City
Pisa
State/Province
Toscana
ZIP/Postal Code
56126
Country
Italy
Facility Name
GSK Investigational Site
City
Heemstede
ZIP/Postal Code
2103 SW
Country
Netherlands
Facility Name
GSK Investigational Site
City
Warszawa
ZIP/Postal Code
00-453
Country
Poland
Facility Name
GSK Investigational Site
City
Belgorod
ZIP/Postal Code
308007
Country
Russian Federation
Facility Name
GSK Investigational Site
City
Kazan
ZIP/Postal Code
420064
Country
Russian Federation
Facility Name
GSK Investigational Site
City
Krasnodar
ZIP/Postal Code
350007
Country
Russian Federation
Facility Name
GSK Investigational Site
City
Moscow
ZIP/Postal Code
107150
Country
Russian Federation
Facility Name
GSK Investigational Site
City
Moscow
ZIP/Postal Code
117049
Country
Russian Federation
Facility Name
GSK Investigational Site
City
Samara
ZIP/Postal Code
443095
Country
Russian Federation
Facility Name
GSK Investigational Site
City
Smolensk
ZIP/Postal Code
214 019
Country
Russian Federation
Facility Name
GSK Investigational Site
City
St.-Petersburg
ZIP/Postal Code
193019
Country
Russian Federation
Facility Name
GSK Investigational Site
City
Bangkok
ZIP/Postal Code
10400
Country
Thailand
Facility Name
GSK Investigational Site
City
Khon Kaen
ZIP/Postal Code
40002
Country
Thailand
Facility Name
GSK Investigational Site
City
Dnepropetrovsk
ZIP/Postal Code
49005
Country
Ukraine
Facility Name
GSK Investigational Site
City
Lugansk
ZIP/Postal Code
91045
Country
Ukraine
Facility Name
GSK Investigational Site
City
Odesa
ZIP/Postal Code
65014
Country
Ukraine
Facility Name
GSK Investigational Site
City
Oleksandrivka Village, Odesa
ZIP/Postal Code
67513
Country
Ukraine
Facility Name
GSK Investigational Site
City
Poltava
Country
Ukraine
12. IPD Sharing Statement
Plan to Share IPD
Yes
IPD Sharing Plan Description
IPD for this study will be made available via the Clinical Study Data Request site.
IPD Sharing Time Frame
IPD is available via the Clinical Study Data Request site (click on the link provided below)
IPD Sharing Access Criteria
Access is provided after a research proposal is submitted and has received approval from the Independent Review Panel and after a Data Sharing Agreement is in place. Access is provided for an initial period of 12 months but an extension can be granted, when justified, for up to another 12 months.
IPD Sharing URL
https://clinicalstudydatarequest.com/Posting.aspx?ID=20279
Learn more about this trial
Long-Term Safety Study of Retigabine Immediate Release (IR) as Adjunctive Therapy in the Treatment of Adults With Partial-Onset Seizures (POS)
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