Evaluate efficacy and safety of Eslicarbazepine acetate (ESL) monotherapy during long-term treatment.

Eslicarbazepine acetate (ESL) is a once-daily antiepileptic drug (AED) approved for the treatment of focal (partial-onset) seizures, including as monotherapy for newly diagnosed adults with focal seizures.

Patients who completed the double-blind Phase III trial and remained seizure free for ≥6 months at the last evaluated dose, were eligible to enter a 2-year open-label extension (OLE) study (311-EXT), in which all patients received open-label treatment with flexibly-dosed ESL monotherapy.

Efficacy: seizure freedom rate and overall treatment satisfaction. Safety: treatment-emergent adverse events (TEAEs), treatment-related TEAEs, serious TEAEs, TEAEs by severity, and TEAEs leading to discontinuation.

206 patients entered the OLE study (ESL/ESL, n=109; CBZ-CR/ESL, n=97). The majority of patients, (89.3%; n= 184), remained under ESL monotherapy throughout the OLE study (ESL/ESL, n=96 ; CBZ-CR/ESL, n=88), and maintained the same ESL dose (ESL/ESL, 95.8%; CBZ/ESL, 89.8%).

158/184 (85.9%) of patients maintained seizure freedom during the 2-year. Treatment satisfaction was rated as ‘very good’ or ‘good’ by 100% of patients and investigators.

109/184 (59.2%) patients reported TEAEs (ESL/ESL, 53.1%; CBZ-CR/ESL, 65.9%). The majority of TEAEs were of mild or moderate intensity (77.7% overall; ESL/ESL, 69.8%; CBZ-CR/ESL, 86.4%). Serious TEAEs were reported for 12/184 (6.5%) patients overall (ESL/ESL, 7.3%; CBZ-CR/ESL, 5.7%). No serious TEAE was reported for more than one patient. Withdrawal due to TEAEs was low and similar between groups (ESL/ESL, 3.1%; CBZ-CR/ESL, 4.5%).

Efficacy of ESL monotherapy was largely sustained during this 2-year OLE study in patients initially treated with ESL monotherapy and in those who transitioned from controlled-release carbamazepine (CBZ-CR) monotherapy.

Long-term safety/tolerability of ESL monotherapy was consistent with what has been previously reported. These findings support the use of ESL as long-term monotherapy in newly diagnosed patients with focal epilepsy, including those previously treated with CBZ-CR.