Study of Retigabine Immediate Release as Adjunctive Therapy to Specified Monotherapy Antiepileptic Treatments in Adults With Partial-Onset Seizures
Condition: Epilepsy
MeSH terms: Epilepsy; Seizures
Intervention: Retigabine IR
Intervention description: Flexible dose between 300 mg/day (minimum) and 1200 mg/day (maximum).
Intervention MeSH terms: Ezogabine
Phase: Phase 3
Study type: Interventional
Primary purpose: Treatment
Intervention model: Single Group Assignment
Masking: None (Open Label)
Enrollment: 203.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: No
Keywords: Seizures; retigabine IR; GW582892; Epilepsy; Open label, flexible dose; Partial-onset seizures

Summary:

      The purpose of this Phase III study is to evaluate the efficacy, safety and tolerability and
      health outcomes of retigabine Immediate Release (IR) as adjunctive therapy to each of the
      following monotherapy Antiepileptic Drug (AED) treatments: carbamazepine/oxcarbazepine,
      lamotrigine, levetiracetam, or valproic acid in adult subjects with partial-onset seizures
      (POS) using a flexible dosing regimen.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Is 18 years of age (men or women)

          -  Has a confident diagnosis of epilepsy with partial-onset seizures i.e., simple or
             complex partial seizures with or without secondary generalization (International
             League Against Epilepsy (ILAE) classification; 1981) for more than 24 weeks prior to
             the start of Baseline phase.

          -  Has experienced at least 4 partial-onset seizures (i.e., simple or complex partial
             seizures with or without secondary generalization) during an 8-week (i.e., 56 days)
             prospective Baseline Phase with at least one partial seizure occurring during each 4
             week (i.e., 28-day) period.

          -  Receiving a stable dose of one of the following AEDs: carbamazepine/oxcarbazepine,
             lamotrigine, levetiracetam or valproic acid. The AED dose must be stable 4 weeks prior
             to start of collection of baseline seizure data (retrospective or prospective) and
             during the Baseline period.

          -  Is able and willing to maintain an accurate and complete daily written seizure
             calendar and functional status diary or has a caregiver who is able and willing to do
             so for the entire duration of the study.

          -  Is able to comply with dosing of study drug, background AED and all study procedures.

          -  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 either of
             non-childbearing potential or child-bearing potential but has a negative pregnancy
             test at Screening and agrees to satisfy one of the contraception methods as listed in
             the protocol, and is 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 a history of generalised epilepsy (e.g. Lennox-Gastaut, Juvenile Myoclonic etc.)

          -  Has had status epilepticus (other than simple partial status epilepticus) within the
             24 weeks prior to Baseline Visit.

          -  Has participated in a previous retigabine study (subjects with documented evidence of
             having received placebo will be eligible).

          -  Is currently or has been abusing substance(s) or other medications in the 12 months
             prior to Baseline visit.

          -  Has 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.

          -  Is currently following or planning to follow the ketogenic diet.

          -  Has been treated with vigabatrin within the past 6 months prior to collection of
             baseline seizure data.

          -  Is planning surgery or implantation of a Vagus Nerve Stimulator (VNS) to control
             seizures during the study.

          -  Is 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.

          -  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.

          -  Has a QTc ≥450 millisecond (msec) or greater than or equal to 480 msec for subjects
             with Bundle Branch Block at the time of screening.

          -  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.

          -  French Subjects: the French subject has participated in any study using an
             investigational drug during the previous 30 days or 5 half-lives (whichever is
             longer).