Last updated: 07/17/2024 15:41:27
A Long-term, Safety, Tolerability, and Efficacy Study of Retigabine Immediate-release (IR) in Asian Adults with Partial Onset Seizures
EudraCT ID
Not applicable
EU CT Number
Not applicable
Trial status
Study complete
Study complete
Trial overview
Official title: A Multicentre, Open-label, Long-term, Safety, Tolerability, and Efficacy Study of Retigabine Immediate-release (IR) in Asian Adults with Partial Onset Seizures (Extension of Study RTG114855)
Trial description: This is a multicentre, long-term, open-label extension (OLE) study to assess the long-term safety, tolerability and efficacy of retigabine immediate-release (IR) as adjunctive therapy in adult Asian subjects with drug-resistant partial-onset seizures (POS).
Primary purpose:
Treatment
Trial design:
Single Group Assignment
Masking:
None (Open Label)
Allocation:
Not applicable
Primary outcomes:
Number of participants with treatment emergent (TE) serious adverse events (SAEs) and non-SAEs
Timeframe: Up to 4 years
Percentage of participants with TEAEs leading to study discontinuation
Timeframe: Up to 4 years
Number of participants with potential clinical concern (PCC) values of change from Baseline for vital signs
Timeframe: Baseline and up to 4 years
Number of participants with PCC values of change from Baseline for body weight
Timeframe: Baseline and up to 4 years
Number of participants with PCC values of change from Baseline for electrocardiogram (ECG) parameters
Timeframe: Baseline and up to 4 years
Change from Baseline in basophils, eosinophils, lymphocytes, monocytes, platelet count, total neutrophils, and white blood cell count (WBC)
Timeframe: Baseline and up to 4 years
Change from Baseline in hematocrit level
Timeframe: Baseline and up to 4 years
Change from Baseline in hemoglobin and mean corpuscle hemoglobin concentration (MCHC)
Timeframe: Baseline and up to 4 years
Change from Baseline in mean corpuscle hemoglobin (MCH) level
Timeframe: Baseline and up to 4 years
Change from Baseline in mean corpuscle volume (MCV) and mean platelet volume (MPV)
Timeframe: Baseline and up to 4 years
Change from Baseline in red blood cell (RBC) count
Timeframe: Baseline and up to 4 years
Change from Baseline in red cell distribution width (RDW)
Timeframe: Baseline and up to 4 years
Change from Baseline in alanine amino transferase (ALT), alkaline phosphatase (Alk. phosph.), aspartate aminotransferase (AST), creatine kinase (CK), gamma glutamyl transferase (GGT) and lactate dehydrogenase (LD)
Timeframe: Baseline and up to 4 years
Change from Baseline in albumin and total protein
Timeframe: Baseline and up to 4 years
Change from Baseline in blood urea nitrogen (BUN)/creatinine ratio
Timeframe: Baseline and up to 4 years
Change from Baseline in calcium, carbon dioxide (CO2) content/Bicarbonate (Bicarb), chloride, glucose, magnesium, potassium, sodium, urea/BUN
Timeframe: Baseline and up to 4 years
Change from Baseline in creatinine, direct bilirubin, total bilirubin, and uric acid
Timeframe: Baseline and up to 4 years
Change from Baseline in urine albumin/creatinine ratio
Timeframe: Baseline and up to 4 years
Number of participants with abnormal urinalysis values (categorical data)
Timeframe: Up to 4 years
Specific gravity of urine at indicated time points
Timeframe: Up to 4 years
Potential of hydrogen (pH) of urine at indicated time points
Timeframe: Up to 4 years
Change from Baseline in urine creatinine concentration
Timeframe: Baseline and up to 4 years
Change from Baseline in American Urological Association (AUA) symptom scale scores
Timeframe: Baseline and up to 4 years
Change from Baseline in post-void residual (PVR) bladder ultrasound volumes
Timeframe: Baseline and up to 4 years
Number of participants with suicidal ideation or behavior during treatment assessed by Columbia-Suicide Severity Rating Scale (C-SSRS)
Timeframe: Up to 4 years
Number of participants who discontinued from RTG
Timeframe: Up to 4 years
Percentage of participants with retinal pigmentary abnormalities
Timeframe: Up to 4 years
Percentage of participants with pigmentation of non-retinal ocular tissues
Timeframe: Up to 4 years
Percentage of participants with dermatologist-confirmed abnormal discoloration
Timeframe: Up to 4 years
Percentage of participants with a clinically significant decrease in visual acuity from initial examination
Timeframe: Up to 4 years
Percentage of participants with decrease in confrontational visual field from initial examination
Timeframe: Up to 4 years
Percentage of responders to POS frequency
Timeframe: Up to 4 years
Percent change from Baseline in 28-day total POS frequency
Timeframe: Baseline and up to 4 years
Number of participants with resolution of abnormal eye pigmentation after discontinuation of RTG
Timeframe: Up to 1.4 years
Number of participants with resolution of dermatologist-confirmed abnormal discoloration after discontinuation of RTG
Timeframe: Up to 1.4 years
Secondary outcomes:
Not applicable
Interventions:
Enrollment:
30
Primary completion date:
2016-14-12
Observational study model:
Not applicable
Time perspective:
Not applicable
Clinical publications:
Neil Brickel, Karen Hewett, Kirsty Rayner, Susan McDonald, Jeni De’Ath, Jerzy Daniluk, Kalpesh Joshi, Marie Catherine Boll, Tiamkao Somsak, Olga Vorobyeva, James Cooper.Safety of retigabine in adults with partial-onset seizures after long-term exposure: focus on unexpected ophthalmological and dermatological events.Epilepsy Behav.2020;102:106580
DOI: 10.1016/j.yebeh.2019.106580
PMID: 31731109
Medical condition
Epilepsy
Product
retigabine
Collaborators
Not applicable
Study date(s)
April 2013 to September 2017
Type
Interventional
Phase
3
Participation criteria
Sex
Female & Male
Age
18+ years
Accepts healthy volunteers
No
- The subject has successfully completed the Maintenance Phase and Transition Phase of Study RTG114855.
- The subject is expected, in the opinion of the investigator, to benefit from participation in this OLE study.
- Has met any of the withdrawal criteria in the parent study (RTG114855) or has, in the opinion of the investigator, clinically significant abnormal laboratory or ECG findings that preclude entry into RTG114873.
- Is planning to begin treatment with an investigational drug (other than retigabine) and/or an experimental device for the treatment of epilepsy or any other medical condition.
Inclusion and exclusion criteria
Inclusion criteria:
- The subject has successfully completed the Maintenance Phase and Transition Phase of Study RTG114855.
- The subject is expected, in the opinion of the investigator, to benefit from participation in this OLE study.
- The subject or the caregiver is able and willing to maintain an accurate and complete written daily 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 enrol and participate in the study if she is of: nonchildbearing potential (i.e., physiologically incapable of becoming pregnant, including any female who is premenarchal or postmenopausal), premenopausal females with a documented (medical report verification) hysterectomy with or without oophorectomy, or bilateral oophorectomy when reproductive status has been confirmed by hormone level assessment, and postmenopausal females defined as being amenorrhoeic for >1 year with an appropriate clinical profile (e.g., age appropriate, history of vasomotor symptoms). However, if indicated, this should be confirmed by oestradiol and follicle stimulating hormone levels consistent with menopause (according to local laboratory ranges). Women who have not been confirmed as postmenopausal should be advised to use contraception.
- Childbearing potential, has a negative urine or serum pregnancy test at Screening.
- Is not pregnant or lactating or planning to become pregnant during the study.
Exclusion criteria:
- Has met any of the withdrawal criteria in the parent study (RTG114855) or has, in the opinion of the investigator, clinically significant abnormal laboratory or ECG findings that preclude entry into RTG114873.
- Is planning to begin treatment with an investigational drug (other than retigabine) and/or an experimental device for the treatment of epilepsy or any other medical condition.
- Has any medical condition that, in the investigator’s judgement, is considered to be clinically significant and could potentially affect subject safety or study outcome, including but not limited to clinically significant cardiac, renal, or hepatic condition; or a condition that affects the absorption, distribution, metabolism, or excretion of drugs.
- Is unwilling or unable to follow the study procedures or reporting of AEs.
- Has active suicidal plan/intent or has had active suicidal thoughts in the past 6 months or has history of suicide attempt in the last 2 years or >1 lifetime suicide attempt. -
Trial location(s)
Study documents
Clinical study report
Available language(s): English
Protocol
Available language(s): English
If you wish to request for full study report, please contact - [email protected]
Results overview
Results posted on ClinicalTrials.gov
Recruitment status
Study complete
Actual primary completion date
2016-14-12
Actual study completion date
2017-13-09
Plain language summaries
Plain language summaries of clinical trial results for Phase 2-4 clinical trials that were initiated on or after January 2022 will be posted by GSK within one year following study completion.
Additional information about the trial
Additional information
Not applicable
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