Responder rate was defined as the percentage of participants with at least a 50% reduction in 28-day partial seizure frequency from baseline during the maintenance phase (Week 4 - Week 16). The percent change in partial seizure frequency in the maintenance phase was the change from baseline in partial seizure frequency * 100, divided by the partial seizure frequency at the baseline visit.

The modified full analysis set (MFAS) included all participants who received at least 1 dose of the study drug and who had at least one baseline seizure. Participants who discontinued during first 4 weeks titration phase were regarded as missing and were excluded from the analysis.

The partial seizure frequency for the baseline period was the total number of partial seizures recorded for that period at Visit 0 (week 0). For each participant's final visit, the 28 day partial seizure frequency equals total number of partial seizures since the last visit * 28 divided by total number of days since the last visit. For percent change from baseline: change from baseline in partial seizure frequency*100 divided by partial seizure frequency at baseline visit.

MFAS included all participants who received at least 1 dose of the study drug and who had at least one baseline seizure. Participants who discontinued during first 4 weeks titration phase were regarded as missing and were excluded from the analysis. Analysis was done using last observation carried forward (LOCF) method.

Participants were regarded as seizure-free if no seizures (partial or other) were reported for the participant during the last 4 weeks in the study.

MFAS: Data collected during the titration phase, i.e. prior to Visit 2 (Week 4) were not analyzed for this endpoint. Only participants who did not discontinue in the first 4 weeks after the baseline visit (titration phase) and had at least 4 weeks of seizure data during the maintenance phase were analyzed for this endpoint.

VAS-A consists of a visual analog scale ranging from, 0 mm (no anxiety) to 100 mm (extreme anxiety).

Full Analysis Set (FAS): Included all participants who received at least 1 dose of study drug. Participants who did not have the minimum required data for the statistical summary were treated as missing. Analysis was done using LOCF method.

CGI-S: 7-point clinician rated scale to assess severity of participant's current illness state; range: 1 (normal - not ill at all) to 7 (among the most extremely ill patients). Higher score = more affected.

FAS: Included all participants who received at least 1 dose of study drug. Participants who did not have the minimum required data for the statistical summary were treated as missing.

The CGI-C scale measures a physician's global impression of a participant's clinical condition at final visit in terms of change relative to the start of treatment (CGI-C).

At final visit, the participants CGI-C will be categorized into a three point scale as: improvement: CGI response of very much improved, much improved or minimally improved; no change: CGI response of no change; worsening: CGI response of very much worse, much worse or minimally worse.

FAS: Included all participants who received at least 1 dose of study drug. Participants who did not have the minimum required data for the statistical summary were treated as missing.

MOS: participant rated questionnaire, assess sleep quality and quantity. Consists of 9-item overall sleep problems index (length of time to fall asleep, how many hours of sleep each night during past 4 weeks); 7 subscales rated 1 (all the time) to 6 (none of the time): sleep disturbance, snoring, awaken short of breath (SOB) or with a headache, somnolence adequacy, and sleep quantity. Transformed scores (actual raw score minus lowest possible score divided by possible raw score range multiplied by 100); sub-scales total score range= 0-100; higher score indicates greater intensity of attribute.

The FAS included all participants who received at least 1 dose of the study drug and had at least one efficacy measurement.

Concomitant drug (any drug other than, and in addition to, the study drug) taken for any period of time during the study.

Safety analysis set included all enrolled participants who received 1 dose of study medication.

Participants who had a concomitant co-morbidity during the study for any period of time from baseline through to Week 16 (Final Visit); participants with more than one concomitant co-morbidity were counted for each of the co-morbidity classes applicable.

Safety analysis set included all enrolled participants who received 1 dose of study medication.