A multicenter, double-blind, randomized, placebo-controlled, 3 parallel groups, dose-ranging trial evaluating the efficacy and safety of ucb 34714 used as adjunctive treatment at doses of 50 and 150 mg/day in b.i.d. administration (oral capsules of 25 mg) for a maximum of 12 weeks in subjects from 16 to 65 years with refractory epilepsy suffering from partial onset seizures whether or not secondarily generalized - ucb 34714 dose-ranging

INTERVENTION: Product Code: ucb 34714 Pharmaceutical Form: Capsule* INN or Proposed INN: not yet available CAS Number: 357336‐20‐0 Current Sponsor code: ucb 34714 Other descriptive name: (a1S, 4R)‐a‐ethyl‐2‐oxo‐4‐propyl‐ 1‐pyrrolidineacetamide Concentration unit: mg milligram(s) Concentration type: equal Concentration number: 25‐ Pharmaceutical form of the placebo: Capsule* Route of administration of the placebo: Oral use CONDITION: Epilepsy ‐ Refractory Partial Onset Seizure wheter or not secondarily generalized. ; MedDRA version: 7.1 Level: LLT Classification code 10061334 PRIMARY OUTCOME: Main Objective: To evaluate efficacy of ucb 34714 at the doses of 50 and 150 mg/day in b.i.d. administration in reducing seizure frequency in subjects with focal epilepsy not fully controlled despite treatment with 1 or 2 concomitant AED(s). Primary end point(s): The intention‐to‐treat population (ITT) will consist of all randomized subjects who took at least one dose of trial medication.; ; The per‐protocol population (PP) is a subset of the intention‐to‐treat population, consisting of those subjects who had no major protocol deviations affecting the primary efficacy variable, as confirmed during a pre‐analysis meeting prior to unblinding of the data.; ; The analyses will be based on the ITT population unless stated otherwise.; ; The periods considered in the definition of efficacy and safety variables are the following:; •Baseline Period (V1 until V2).; •Up‐titration period (V2 to V5).; •Treatment Period (V2 until the earlier of V8 and Early Discontinuation Visit).; •Maintenance Period (V5 until the earlier of V8 and Early Discontinuation Visit).; •Conversion Period (V8 until V11).; •Down‐titration Period (V8 or Early Discontinuation Visit until V11).; •Post‐treatment Period (V11 until V12).; ; Efficacy variables; Seizure frequency per week will be derived from the seizure count information recorded on the DRC and is defined as the number of seizures standardized to a seven day period. It is computed as the number of seizures recorded over the period, divided by the total number of days in that period, multiplied by 7.; ; The primary efficacy variable is the partial onset seizure frequency per week (type I) over the Maintenance Period.; ; The secondary efficacy variables are as follows:; •Seizure frequency per week for all seizures (types I+II+III) over the Maintenance Period.; •Reductions and percentage reductions from Baseline in seizure frequency per week for partial onset seizures (type I) and for all seizures (types I+II+III) over the Maintenance Period.; •Responder rate in partial onset seizures (type I) over the Maintenance Period. A responder is defined as a subject with a = 50% reduction in seizure frequency per week from the Baseline Period to the Maintenance Period.; •Response to treatment in partial onset seizures (type I) over the Maintenance Period. The percentage reduction from Baseline in partial seizure frequency per week over the Maintenance Period will be grouped in 4 categories: < ‐25%, ‐25% to < 25%, 25% to < 75%, 75% to 100%. ; •Percentage of seizure‐free subjects over the Maintenance Period.; •Percentage of seizure‐free days over Baseline and Maintenance Periods.; ; Exploratory variables; •Patient’s Global Evaluation Scale at V8 or Early Discontinuation Visit.; •Investigator’s global Evaluation Scale at V8 or Early Discontinuation Visit.; •Health‐Related Quality of Life (QOLIE‐31‐P) at V2 and at V8 or Early Discontinuation Visit.; •Hospital Anxiety and Depression Scale (HADS) at V2 and at V8 or Early Discontinuation Visit.; •Medical resources used over the Baseline Period and over the Evaluation Period, including health care provider consultations not foreseen by the protocol, concurrent medical procedures, concomitant medications, hospitalizations and length of stay.; ; Safety variables; Safety assessments will be made using adverse events, laboratory tests (including blood and urine), electrocardiogram (ECG), physical and neurological examinations, vital signs and body weight.; ; The number of subjects who follow the fallback option, the time to fallback and the reason of fallback will also be investigated in order to give the most accurate information on the data used for the primary efficacy analysis.; ; Pharmacokinetic variables; •ucb 34714 (parent compound only): plasma levels in all subjects, at each specified visit under trial drug; •Concomitant AED(s) (and/or relevant metabolites): plasma levels in all subjects at baseline and at each specified visit under trial drug.; ; Secondary Objective: ‐ To evaluate the dose/clinical response relationship and narrow down the dose range of clinical interest.; ‐ To explore tolerability of ucb 34714 in the same population.; ‐ To collect data on seizure‐free days and seizure‐free subjects.; ; INCLUSION CRITERIA: •An IEC approved written informed consent signed and dated by the subject or by parent(s) or legal representative. The consent form or a specific assent form, where required, will be signed and dated by minors. •Well‐characterized focal epilepsy or epileptic syndrome according to the ILAE classification, which was supported by adequate diagnostic documentation (EEG and MRI/CT scan). •Subjects with a history of partial onset seizures whether or not secondarily generalized. •Subjects having at least 4 partial onset seizures whether or not secondarily generalized during the 4‐week Baseline Period and at least 2 partial onset seizures whether or not secondarily generalized per month during the 3 months preceding V1. •Subjects being uncontrolled while treated by 1 or 2 concomitant AED(s). Vagal Nerve Stimulation (VNS) is allowed and will not be counted as a concomitant AED. •Concomitant AED(s) being stable from at least 1 month before Visit 1 and durin