Evaluation of long-term safety, tolerability, and behavioral outcomes with adjunctive rufinamide in pediatric patients (≥1 to <4 years old) with Lennox-Gastaut syndrome: Final results from randomized study 303.

OBJECTIVE: Evaluate the long-term safety, tolerability, and behavioral effects of adjunctive rufinamide in pediatric patients (≥1 to <4 years old) with inadequately controlled seizures associated with Lennox-Gastaut syndrome (LGS). METHODS: Study 303 (ClinicalTrials.gov identifier NCT01405053) was a multicenter, randomized, open-label, Phase III trial. Patients were randomized (2:1) to oral suspension rufinamide (≤45 mg/kg/day) or any other investigator-chosen antiepileptic drug (AED) for a 2-year treatment period. Primary safety/tolerability assessments included monitoring of treatment-emergent adverse events (TEAEs) and serious TEAEs. Behavioral effects were assessed via the Child Behavior Checklist (CBCL) using the Total Problems score and change from baseline in CBCL Total Problems score. CBCL subscores were also evaluated. RESULTS: The Safety Analysis Set included 37 patients (rufinamide: n = 25; any other AED: n = 12). TEAE incidence was similar between the rufinamide (88.0%) and any-other-AED groups (83.3%); serious TEAE incidence was also similar between treatment groups (40.0% and 41.7%, respectively). Between treatment groups, the difference in the least squares mean CBCL Total Problems score across time was not significant (p = 0.7083), behavior outcomes were similar across all endpoints, and there were no consistent trends in CBCL subscores. SIGNIFICANCE: Long-term (2 years) adjunctive rufinamide was well tolerated in pediatric patients with LGS. Behavioral outcomes were comparable between the rufinamide and any-other-AED groups, however the small sample size and difficulties assessing behavior in this population should be noted. The challenges of this study raise the issue of revising how studies in very young children with rare and complex epilepsies are performed.

Dosing considerations for rufinamide in patients with Lennox-Gastaut syndrome: Phase III trial results and real-world clinical data.

PURPOSE: Lennox-Gastaut syndrome (LGS), a rare, severe form of childhood-onset epilepsy, is difficult to control. Rufinamide is indicated for adjunctive treatment of seizures associated with LGS in adults and pediatric patients aged ≥1 year. In clinical practice, rufinamide dosing and titration may differ from the trial setting. Here, rufinamide clinical trial data are compared with real-world experience to provide insight into optimal dosing and titration strategies. METHODS: Rufinamide Phase III and open-label extension (OLE) studies were reviewed; effect of titration and dose on adverse events (AEs) and concomitant AED use were analyzed. Real-world studies of rufinamide in LGS were identified via PubMed search. Clinical data were extracted and compared. RESULTS: Results demonstrated that a rapid titration schedule (7 or 14 days) of rufinamide was tolerable for most patients and resulted in highly significant reductions in total and tonic-atonic seizures, with efficacy and tolerability sustained over 3 years. The most common AEs during the Phase III study - somnolence, vomiting, and pyrexia - occurred during the first 3 weeks of treatment, and a small subset of patients were unable to reach target dose in that time. Use of concomitant AEDs had no clinically significant effect on plasma concentrations of rufinamide. Data from real-world clinical studies are consistent with the Phase III and OLE study results. However, relative to those used in clinical trials, lower doses and slower titration schedules were commonly employed in real-world settings. CONCLUSIONS: A lower dose and slower titration schedule ("low and slow") may reduce incidence of AEs without compromising efficacy of rufinamide in LGS.