Treatment-emergent adverse events (TEAEs) were defined as those events which started on or after the date of first dose of investigational medicinal product (IMP), or events in which severity worsened on or after the date of first dose of study medication. The event does not necessarily have a causal relationship with that treatment or usage.

The Safety Set (SS) consisted of all participants who took at least 1 dose of study drug.

An AE is any untoward medical occurrence in a participant or trial participant that is administered a drug or biologic (medicinal product) or that is using a medical device. The event does not necessarily have a causal relationship with that treatment or usage.

The Safety Set (SS) consisted of all participants who took at least 1 dose of study drug.

A serious adverse event (SAE) is any untoward medical occurrence that at any dose:

• Results in death
• Is life-threatening
• Requires in patient hospitalization or prolongation of existing hospitalization
• Is a congenital anomaly or birth defect
• Is an infection that requires treatment parenteral antibiotics
• Other important medical events which based on medical or scientific judgement may jeopardize the patients or may require medical or surgical intervention to prevent any of the above.

The Safety Set (SS) consisted of all participants who took at least 1 dose of study drug.

The 28 day adjusted seizure frequency was calculated by dividing the number of partial seizures by the number of days for which the diary was completed, and multiplying the resulting value by 28.

Baseline values for seizure frequency were calculated based on the seizure diary data collected during the baseline period of the previous double-blind studies: N01114 [NCT00175929], N01252 [NCT00490035] and N01254 [NCT00504881].

The Partial Onset Seizure (POS) Efficacy Analysis Set consisted of all participants with POS who took at least 1 dose of study drug and had at least 1 seizure diary day during the Evaluation Period.

The percent change from the previous study baselines, in Partial Onset Seizure (POS) (Type I) frequency per 28 days is defined as:

(the value at the previous study baselines) minus (the value at each time-points during the evaluation period) divided by the value at the previous study baselines.

Baseline values for seizure frequency were calculated based on the seizure diary data collected during the baseline period of the previous double-blind studies: N01114 [NCT00175929], N01252 [NCT00490035] and N01254 [NCT00504881].

The Partial Onset Seizure (POS) Efficacy Analysis Set consisted of all participants with POS who took at least 1 dose of study drug and had at least 1 seizure diary day during the Evaluation Period.

A responder is defined as a participant with a ≥ 50% reduction in seizure frequency from the Baseline Period of the previous study.

Baseline values for seizure frequency were calculated based on the seizure diary data collected during the baseline period of the previous double-blind studies: N01114 [NCT00175929], N01252 [NCT00490035] and N01254 [NCT00504881].

The Partial Onset Seizure (POS) Efficacy Analysis Set consisted of all participants with POS who took at least 1 dose of study drug and had at least 1 seizure diary day during the Evaluation Period.