EpilepsyPhase 3IRNCT01336621
Long-Term Safety Study of Retigabine Immediate Release (IR) as Adjunctive Therapy in the Treatment of Adults With Partial-Onset Seizures (POS)
A Phase 3 study testing Retigabine IR in people with Epilepsy, run by GlaxoSmithKline at 31 sites in 10 countries.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Epilepsy
- What is being tested?
- Retigabine IR
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 98 participants
- Where
- 31 sitesin 10 countries
- Study dates
- 21 Feb 2011to 13 Sep 2017
- Phase
- Phase 3
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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.
Who cannot join
- 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.
Trial locations and contacts
31 sites in 10 countries.
31 sites in 10 countries
Russia8 sites
GSK Investigational Site
Belgorod, 308007
GSK Investigational Site
Kazan', 420064
GSK Investigational Site
Krasnodar, 350007
GSK Investigational Site
Moscow, 107150
GSK Investigational Site
Moscow, 117049
GSK Investigational Site
Saint Petersburg, 193019
GSK Investigational Site
Samara, 443095
GSK Investigational Site
Smolensk, 214 019
Italy7 sites
GSK Investigational Site
Bologna, Emilia-Romagna, 40139
GSK Investigational Site
Foggia, Apulia, 71100
GSK Investigational Site
Genoa, Liguria, 16153
GSK Investigational Site
Pisa, Tuscany, 56126
GSK Investigational Site
Rome, Lazio, 00163
GSK Investigational Site
Rome, Lazio, 00185
GSK Investigational Site
Torrette Di Ancona, The Marches, 60126
Ukraine5 sites
GSK Investigational Site
Dnipro, 49005
GSK Investigational Site
Luhansk, 91045
GSK Investigational Site
Odesa, 65014
GSK Investigational Site
Oleksandrivka Village, Odesa, 67513
GSK Investigational Site
Poltava
Bulgaria3 sites
GSK Investigational Site
Plovdiv, 4000
GSK Investigational Site
Sofia, 1113
GSK Investigational Site
Sofia, 1431
France2 sites
GSK Investigational Site
Limoges, 87042
GSK Investigational Site
Strasbourg, 67098
Thailand2 sites
GSK Investigational Site
Bangkok, 10400
GSK Investigational Site
Khon Kaen, 40002
Germany1 site
GSK Investigational Site
Bielefeld, North Rhine-Westphalia, 33617
About this study
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)
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.
Read the 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.
- Conditions
- Epilepsy
- Being tested
- Retigabine IR
- Keywords
- Partial-onset seizures, retigabine IR, Open Label Extension, GW582892, Epilepsy
- Medical subject headings
- Epilepsy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Retigabine IRDrug
Flexible dose between 300 mg/day (minimum) and 1200 mg/day (maximum)
| Study group | Role | What they receive |
|---|---|---|
| Retigabine IR | Experimental | Open label flexible dose between 300 mg/day (Minimum) and 1200 mg/day (maximum). Receives: Drug: Retigabine IR |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: Up to 5.8 years
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.
Measured: Up to 2.6 years
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.
Measured: Up to 5.8 years
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.
Measured: Up to 5.8 years
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.
Measured: Up to 5.8 years
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.
Measured: Up to 5.8 years
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.
Measured: Up to 5.8 years
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.
Measured: Up to 5.8 years
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.
Measured: Up to 5.8 years
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).
Measured: Baseline and up to 5.8 years
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).
Measured: Baseline and up to 5.8 years
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).
Measured: Up to 5.8 years
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).
Measured: Up to 5.8 years
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).
Measured: Up to 5.8 years
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).
Measured: Baseline and up to 5.8 years
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).
Measured: Baseline and up to 5.8 years
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).
Measured: Baseline and up to 5.8 years
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).
Measured: Baseline and up to 5.8 years
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).
Measured: Baseline and up to 5.8 years
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).
Measured: Baseline and up to 5.8 years
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).
Measured: Baseline and up to 5.8 years
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).
Measured: Baseline and up to 5.8 years
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).
Measured: Baseline and up to 5.8 years
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).
Measured: Baseline and up to 5.8 years
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).
Measured: Up to 5.8 years
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).
Measured: Baseline and up to 5.8 years
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).
Measured: Baseline and up to 5.8 years
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).
Measured: Baseline and up to 5.8 years
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).
Measured: Baseline and up to 5.8 years
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).
Measured: Baseline and up to 5.8 years
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).
Measured: Baseline and up to 5.8 years
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.
Measured: Up to 5.8 years
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).
Measured: Up to 5.8 years
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.
Measured: Up to 5.8 years
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.
Measured: Up to 5.8 years
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.
Measured: Up to 2.6 years
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.
Measured: Up to 2.6 years
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.
Measured: Up to 2.6 years
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.
Measured: Up to 2.6 years
Secondary outcomes (4)
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.
Measured: Baseline and up to 5.8 years
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.
Measured: Baseline and up to 5.8 years
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.
Measured: Baseline and up to 5.8 years
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.
Measured: Up to 5.8 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Apr 2011 (estimated)
- Study start21 Feb 2011
- Primary completion14 Dec 2016
- Study completion13 Sep 2017
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for EpilepsyStudies of the same condition, open and under way.
- More trials run by GlaxoSmithKlineThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 98 participants (actual)
Sponsor and investigators
- Lead sponsor
- GlaxoSmithKline
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- GSK Clinical Trials, Study director, GlaxoSmithKline
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01336621
- Sponsor's protocol ID
- 113413
- Other IDs
- 2010-022777-34
- Acronym
- IR
- Status last verified
- Mar 2020
- First submitted
- 10 Mar 2011
- Last updated
- 11 Mar 2020
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: IPD for this study will be made available via the Clinical Study Data Request site.
Study at a glance
From the registry record, last updated by the sponsor on 11 Mar 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- 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)
- ClinicalTrials.gov ID
- NCT01336621
- Acronym / sponsor ID
- IR / 113413
- Conditions
- Epilepsy
- Keywords
- Partial-onset seizures, retigabine IR, Open Label Extension, GW582892, Epilepsy
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 98 participants (actual)
- Lead sponsor
- GlaxoSmithKlineIndustry (pharma, biotech, devices)
- Study start
- 21 Feb 2011 (actual)
- Primary completion
- 14 Dec 2016 (actual)
- Study completion
- 13 Sep 2017 (actual)
- First posted
- 18 Apr 2011 (estimated)
- Results
- Posted 26 Feb 2018
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Retigabine IR | Experimental | Drug: Retigabine IROpen label flexible dose between 300 mg/day (Minimum) and 1200 mg/day (maximum). |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (8 listed)
- 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).
Key exclusion criteria (7 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Retigabine IRFlexible dose between 300 mg/day (minimum) and 1200 mg/day (maximum) | Drug | Retigabine IR |
Primary outcome
Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Serious AEs (TESAEs): Safety Population
Time frame: Up to 5.8 years
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
Time frame: Up to 2.6 years
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
Time frame: Up to 5.8 years
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
Time frame: Up to 5.8 years
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)
Time frame: Up to 5.8 years
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
Time frame: Up to 5.8 years
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
Time frame: Up to 5.8 years
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
Time frame: Up to 5.8 years
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
Time frame: Up to 5.8 years
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
Time frame: Baseline and up to 5.8 years
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
Time frame: Baseline and up to 5.8 years
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
Time frame: Up to 5.8 years
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
Time frame: Up to 5.8 years
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
Time frame: Up to 5.8 years
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
Time frame: Baseline and up to 5.8 years
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
Time frame: Baseline and up to 5.8 years
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
Time frame: Baseline and up to 5.8 years
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
Time frame: Baseline and up to 5.8 years
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
Time frame: Baseline and up to 5.8 years
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
Time frame: Baseline and up to 5.8 years
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
Time frame: Baseline and up to 5.8 years
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
Time frame: Baseline and up to 5.8 years
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
Time frame: Baseline and up to 5.8 years
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
Time frame: Baseline and up to 5.8 years
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
Time frame: Up to 5.8 years
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
Time frame: Baseline and up to 5.8 years
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
Time frame: Baseline and up to 5.8 years
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
Time frame: Baseline and up to 5.8 years
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
Time frame: Baseline and up to 5.8 years
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
Time frame: Baseline and up to 5.8 years
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
Time frame: Baseline and up to 5.8 years
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
Time frame: Up to 5.8 years
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
Time frame: Up to 5.8 years
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
Time frame: Up to 5.8 years
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
Time frame: Up to 5.8 years
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
Time frame: Up to 2.6 years
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
Time frame: Up to 2.6 years
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
Time frame: Up to 2.6 years
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
Time frame: Up to 2.6 years
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.
4 secondary outcomes
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
Time frame: Baseline and up to 5.8 years
Percent Change From Baseline in 28-day Partial-onset Seizure Frequency
Time frame: Baseline and up to 5.8 years
Number of Participants Experiencing an Increase in 28-day Partial-onset Seizure Frequency From Baseline
Time frame: Baseline and up to 5.8 years
Number of Participants Who Remained Seizure-free
Time frame: Up to 5.8 years
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Mar 2020.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: Yes. IPD for this study will be made available via the Clinical Study Data Request site.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
GSK Clinical Trials study director
GlaxoSmithKline
31 sites in 10 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Retigabine IR in people with Epilepsy, run by GlaxoSmithKline at 31 sites in 10 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 11 Mar 2020. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 31 sites in Russia, Italy, Ukraine, Bulgaria, France and 5 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 26 Feb 2018). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Serious AEs (TESAEs): Safety Population (time frame: Up to 5.8 years). The study lists 39 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Mar 2020.