Please assess the completion status of the following clinical trial:

Trial Title: Dose-Optimization, Adjunctive Treatment Study of Ezogabine/Retigabine Immediate Release in Partial-onset Seizures

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: DOUBLE
- Phase: PHASE4
- Number of Arms: 16.0

Eligibility Criteria:
Inclusion Criteria:~* A male or female of 18 years of age or above capable of giving written informed consent~* Have a confident diagnosis of epilepsy for \>=6 months with partial-onset seizures (POS), i.e., simple or complex POS with or without secondary generalization (classified according to the International League Against Epilepsy (ILAE) Guidelines, prior to the Screening Visit~* Currently receiving monotherapy treatment with an antiepileptic drug (AED) at a stable dose for at least 28 days prior to the screening visit (Visit 1). If the subject is taking a barbiturate (e.g., phenobarbital), the dose must be stable for ≥3 months prior to the Screening Visit. Note: Subjects who have received previous adjunctive treatment but are currently taking one AED are eligible for enrolment.~* Investigator-confirmed partial seizure frequency rate of ≥3 partial seizures per 28 days over the 8 weeks preceding the screening visit and must not have been seizure-free for ≥ 21 consecutive days.~* Female of non-child bearing potential, or female of child-bearing potential willing to use protocol-specified methods of contraception to prevent pregnancy during the study.~* Capable to comply with dosing of study drug, background AED, all study procedures and to maintain an accurate and complete daily written Seizure Calendar and Functional Status Diary~Exclusion Criteria:~* Have generalized epilepsy (e.g. Lennox-Gastaut, Juvenile Myoclonic epilepsy, Absence, etc.) or non-epileptic seizures.~* Have had innumerable seizures within the 12-month period prior to the Screening Visit where the individual seizures cannot be counted.~* Have had status epilepticus within 12 months prior to screening~* Have a history of pseudo seizures, non-epileptic events or any other type of psychogenic seizures that could be confused with seizures.~* Have been treated with felbamate or vigabatrin within the 6 months prior to Screening. If a subject has been previously treated with vigabatrin \>6 months prior to Screening, a visual perimetry test performed within 6 months prior to Screening must show normal visual fields or no worsening of recognized visual field abnormalities as compared with prior to vigabatrin treatment~* Benzodiazepines used in any manner other than acute usage as defined in this protocol will be considered concurrent AED usage and will not be permitted~  * Are using Central Nervous System (CNS)-active medication (other than concomitant AED therapy), unless the subject has been stabilized on such medication for at least 1 month prior to the Screening Visit.~* Are using herbal treatments with CNS activity within at least 1 month prior to the Screening Visit~* Have received ezogabine/retigabine in a previous study or have taken POTIGA or TROBALT.~* Are currently following or planning to follow the ketogenic diet~* Have an active Vagus Nerve Stimulator (VNS) to control seizures~* Are planning surgery to control seizures during the study~* Have impaired renal function as judged by a creatinine clearance of \<50 mL/min~* Have a history of urinary retention or risk factors for urinary retention that in the investigator's judgment could potentially affect subject safety.~* Have an average corrected QT interval (QTc), using Bazett's QT correction (QTcB), ≥450msec or ≥480msec for subjects with bundle branch block at the time of the Screening Visit~* Liver function tests: alanine aminotransferase (ALT) is ≥2 times the upper limit of normal (ULN); alkaline phosphatase and bilirubin are \>1.5 × ULN (isolated bilirubin \>1.5 × ULN is acceptable if bilirubin is fractionated and direct bilirubin is \<35%).~* Are suffering from acute or progressive neurological disease, severe psychiatric disease, or severe mental abnormalities that are likely to interfere with the objectives of the study~* Have a history of malignancy within the past 2 years; with the exception of basal cell carcinoma~* Have unstable liver disease \[chronic stable hepatitis B and C are acceptable if subject otherwise meets entry criteria; chronic stable Hepatitis B to be excluded if significant immunosuppressive agents administered due to risk of hepatitis B reactivation\]~* Have 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~* Have an active suicidal plan/intent or have had active suicidal thoughts in the past 6 months. Have history of suicide attempt in the last 2 years or more than 1 lifetime suicide attempt.~* Have a history of substance abuse (alcohol or drugs) or substance dependence within 12 months prior to screening~* Have a known hypersensitivity to any components of the study medication~* Have taken an investigational drug, or used an investigational device, within the previous 30 days prior to screening or plans to take an investigational drug anytime during the study.

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: None
- Healthy Volunteers: t

Study Arms:
- Titration Phase: Ezogabine/Retigabine 300 mg (Type: EXPERIMENTAL): Subjects receive Ezogabine/Retigabine 300 mg equally divided TID over Wk 1
- Titration Phase: Placebo 300 mg (Type: PLACEBO_COMPARATOR): Subjects receive matching Placebo
- Titration Phase: Ezogabine/Retigabine 450 mg (Type: EXPERIMENTAL): Subjects receive Ezogabine/Retigabine 450 mg equally divided TID over Wk 2
- Titration Phase: Placebo 450 mg (Type: PLACEBO_COMPARATOR): Subjects receive matching Placebo
- Dose-Optimization Phase: Ezogabine/Retigabine 600 mg (Type: EXPERIMENTAL): Subjects receive Ezogabine/Retigabine 600 mg equally divided (200 mg TID) over Wk 3 or until they achieve their optimal tolerated dose as assessed by the Investigator
- Dose-Optimization Phase: Placebo 600 mg (Type: PLACEBO_COMPARATOR): Subjects receive matching Placebo
- Dose-Optimization Phase: Ezogabine/Retigabine 750 mg (Type: EXPERIMENTAL): Subjects receive Ezogabine/Retigabine 750 mg equally or unequally divided TID over Wk 4 or until they achieve their optimal tolerated dose as assessed by the Investigator
- Dose-Optimization Phase: Placebo 750 mg (Type: PLACEBO_COMPARATOR): Subjects receive matching Placebo
- Dose-Optimization Phase: Ezogabine/Retigabine 900 mg (Type: EXPERIMENTAL): Subjects receive Ezogabine/Retigabine 900 mg equally or unequally divided TID over Wk 5 or until they achieve their optimal tolerated dose as assessed by the Investigator
- Dose-Optimization Phase: Placebo 900 mg (Type: PLACEBO_COMPARATOR): Subjects receive matching Placebo
- Dose-Optimization Phase: Ezogabine/Retigabine 1050 mg (Type: EXPERIMENTAL): Subjects receive Ezogabine/Retigabine 1050 mg equally or unequally divided TID over Wk 6 or until they achieve their optimal tolerated dose as assessed by the Investigator
- Dose-Optimization Phase: Placebo 1050 mg (Type: PLACEBO_COMPARATOR): Subjects receive matching Placebo
- Dose-Optimization Phase: Ezogabine/Retigabine 1200 mg (Type: EXPERIMENTAL): Subjects receive Ezogabine/Retigabine 1200 mg equally divided (400 mg TID) over Wk 7 or until they achieve their optimal tolerated dose as assessed by the Investigator
- Dose-Optimization Phase: Placebo 1200 mg (Type: PLACEBO_COMPARATOR): Subjects receive matching Placebo
- Maintenance Phase:Ezogabine/Retigabine (Type: EXPERIMENTAL): Subjects receive Ezogabine/Retigabine at the daily dose achieved (equally or unequally divided TID) at the end of the Dose-Optimization Phase for 8 Weeks (600 mg, 750 mg, 900 mg, 1050 mg, or 1200 mg)
- Maintenance Phase: Placebo (Type: PLACEBO_COMPARATOR): Subjects receive matching Placebo

Based on this trial design, predict the completion outcome and termination type (if applicable).