The purpose of this study is to examine the efficacy and safety of Eslicarbazepine acetate (BIA 2-093) when given with other anti-epileptic drugs to treat children with partial seizures whose condition has not been controlled by other drug treatments.

Partial epilepsy, the commonest form of epilepsy, is a difficult condition to treat with many patients continuing to have symptoms despite trying several medications. Lack of efficacy and adverse effects are commonly associated with current anti-epileptic drugs.

This study will examine the efficacy in addition to safety and tolerability of a new anti-epileptic drug, Eslicarbazepine acetate (BIA 2-093), as an adjunctive therapy for refractory partial seizures in children.

The primary analysis variables are:

• The responder rate (the proportion of patients with at least a 50% reduction in standardised seizure frequency)
• The relative reduction in standardised seizure frequency

• Drug: Eslicarbazepine acetate (BIA 2-093)

  Part I - 8-week observational baseline period followed by a 6-week double-blind titration period, a 12-week double-blind maintenance period, a double-blind tapering-off period, and a 4-week observational period.

  The recommended target dose of double-blind study treatment will be 20mg/kg/day.

  Part II: At the end of part I, there is an option to enter a long-term open-label extension period to receive Eslicarbazepine acetate for 1 year.

  Other Name: BIA 2093
• Drug: Eslicarbazepine acetate

  Part I: 8-week observational baseline period followed by a 6-week double-blind titration period, a 12-week double-blind maintenance period, a double-blind tapering-off period, and a 4-week observational period.

  Part II: At the end of part I, there is an option to enter a long-term open-label extension period to receive Eslicarbazepine acetate for 1 year.

  Other Name: BIA 2093

• Eslicarbazepine acetate: Active Comparator
  To receive Eslicarbazepine acetate in addition to concomitant therapy
  Intervention: Drug: Eslicarbazepine acetate (BIA 2-093)
• Placebo: Placebo Comparator
  To receive placebo in addition to concomitant therapy
  Intervention: Drug: Eslicarbazepine acetate

Inclusion Criteria:

• girls of child-bearing potential have to follow reliable and medically acceptable contraceptive method throughout the study
• diagnosis of epilepsy for at least 6 months prior to enrolment
• at least 4 partial-onset seizures in the last month prior to enrolment despite stable therapy with adequate dosage of 1 or 2 AEDs
• at least 4 partial-onset seizures during each 4-week interval of the 8-week baseline period
• previous treatment with three or more AEDs, in their maximum tolerated doses, for at least one month, without seizure control
• current treatment with 1 or 2 AEDs (any except oxcarbazepine); if present, vagus nerve stimulation is considered an AED
• stable dose regimen of AEDs during the 8-week baseline period
• cooperation and willingness to complete all aspects of the study, including hospitalisation if required
• written informed consent to participate in the study in accordance with local legislation

Exclusion Criteria:

• primarily generalised seizures
• baseline seizure frequency substantially different from usual seizure frequency
• known progressive neurological disorders
• history of status epilepticus within the 3 months prior to enrolment
• seizures of non-epileptic origin
• Lennon-Gastaut
• West syndrome
• Major psychiatric disorders
• Previous treatment any study with Eslicarbazepine acetate