title: Long-term efficacy and safety of adjunctive extended-release oxcarbazepine (Oxtellar XR®) in adults with partial-onset seizures.
abstract: OBJECTIVE
  To evaluate long-term outcomes of adjunctive therapy with SPN-804 (Oxtellar XR®, Supernus Pharmaceuticals), an extended-release tablet formulation of oxcarbazepine (OXC), in adults with refractory partial-onset seizures.
  
  
  METHODS
  After completing a 16-week double-blind, placebo-controlled trial of SPN-804 at fixed dosages (1200 or 2400 mg QD), patients entering this open-label extension study were converted in blinded fashion to 1200 mg QD SPN-804 as a target starting dose for long-term treatment. Patients were followed for 1 year, during which SPN-804 dosages could be adjusted up to 2400 mg/day according to clinical response.
  
  
  RESULTS
  Of 214 patients, 84% completed 1-year open-label treatment. Median maintenance SPN-804 dosage was 1200 mg; <10% of patients required 2400 mg. Median 28-day seizure frequency reduction from baseline was 59%; seizure frequency was reduced ≥50% in 58% of patients; 11% were seizure free ≥6 months; and 5% were seizure free ≥1 year. SPN-804 was discontinued due to adverse events in 5% (n = 10). Incidences of each of the most common adverse events (dizziness, headache, diplopia, nausea, vomiting, balance disorder, blurred vision) were ≤15% during 1-year follow-up and occurred most frequently in patients previously naïve to SPN-804. No new safety signals, no clinically significant changes in health status, and no deaths attributable to SPN-804 were observed.
  
  
  CONCLUSIONS
  SPN-804 administered once daily for 1 year was effective as adjunctive therapy in improving seizure control and maintaining therapeutic response in adults with refractory partial-onset seizures. With dosage flexibility, SPN-804 was well tolerated.
authors.affiliation: Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, USA.
authors.forename: S S
authors.initials: SS
authors.lastname: Chung
authors.affiliation: Supernus Pharmaceuticals, Inc., Rockville, MD, USA.
authors.forename: J K
authors.initials: JK
authors.lastname: Johnson
authors.affiliation: Supernus Pharmaceuticals, Inc., Rockville, MD, USA.
authors.forename: S T
authors.initials: ST
authors.lastname: Brittain
authors.affiliation: Supernus Pharmaceuticals, Inc., Rockville, MD, USA.
authors.forename: P
authors.initials: P
authors.lastname: Baroldi
keywords: Oxcarbazepine; adjunctive therapy; extended-release; partial-onset seizures