Long-Term Safety Study of Retigabine Immediate Release (IR) as Adjunctive Therapy in the Treatment of Adults With Partial-Onset Seizures (POS)
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: 98.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: No
Keywords: Partial-onset seizures; retigabine IR; Open Label Extension; GW582892; Epilepsy

Summary:

      The purpose of this Phase III study is to assess the long-term safety, tolerability and
      efficacy of flexibly dosed retigabine Immediate Release (IR) as adjunctive therapy in adult
      subjects with partial-onset seizures. In addition, those subjects who successfully completed
      20 weeks of adjunctive treatment with retigabine IR in the parent study, RGB113905, and who
      were thought to have benefitted from treatment will be provided continued access to
      retigabine IR.
    

Eligibility criteria:

        Inclusion Criteria:

          -  The subject has successfully completed the 20-weeks (4-weeks Titration and 16-weeks of
             Flexible Dose Evaluation Phases) of treatment with retigabine IR as adjunctive therapy
             to one of the pre-specified AEDs in the parent study RGB113905.

          -  The investigator and the subject, or caregiver, if applicable, should consider it
             beneficial for the subject to receive continued retigabine IR therapy.

          -  The subject is able and willing to maintain an accurate and complete daily written
             Seizure Calendar or has a caregiver who is able and willing to maintain an accurate
             and complete daily written Seizure Calendar for the entire duration of the study.

          -  The subject has given written informed consent, or has a legally authorized
             representative who has given written informed consent, prior to the performance of any
             study assessments.

          -  A female subject is eligible to enter and participate in the study if she is of
             non-childbearing potential (i.e., physiologically incapable of becoming pregnant,
             including any female who is pre- menarcheal or post menopausal).

          -  A female subject is eligible to enter and participate in the study if she is
             child-bearing potential and has a negative pregnancy test at Screening, and agrees to
             use one of the contraceptive methods listed in Appendix 3 of the protocol.

          -  A female subject is eligible to enter and participate in the study if she not pregnant
             or lactating or planning to become pregnant during the study.

          -  French subjects only: In France, a subject will be eligible for inclusion in this
             study only if either affiliated to or a beneficiary of a social security category.

        Exclusion Criteria:

          -  Has met any of the withdrawal criteria in the previous RGB113905 study or has
             clinically significant abnormal clinical laboratory or ECG findings not resolved prior
             to entry to the open-label extension study.

          -  Is suffering from acute or progressive neurological disease, severe psychiatric
             disease, or severe mental abnormalities that are likely to interfere with the study
             objectives.

          -  Has any medical condition that, in the investigator's judgment, is considered to be
             clinically significant and could potentially affect subject safety or study outcome,
             including but not limited to: clinically significant cardiac, renal, hepatic
             condition, or a condition that affects the absorption, distribution, metabolism or
             excretion of drugs.

          -  Has any abnormality on 12-lead ECG at Screening which is clinically significant in the
             opinion of the investigator, or has QTc (either QTcB Bazett's correction or QTcF
             Fridericia's correction) >500 msec or >530 msec for subjects with Bundle Branch Block
             or an increase in QTc of >60 msec from Baseline in the parent study.

          -  Is unwilling or inability to follow the study procedures or reporting of AEs.

          -  Is planning on following a ketogenic diet or planning surgery or implantation of a
             Vagus Nerve Stimulator (VNS) to control seizures during the study. Note: Subjects who
             already have a VNS implanted which is functional may be permitted to enter the study.

          -  Has active suicidal plan/intent or has had active suicidal thoughts in the past 6
             months. Has history of suicide attempt in the last 2 years or more than 1 lifetime
             suicide attempt.