Abstracts

Rationale: Stiripentol (STP) is indicated for the treatment of seizures associated with Dravet syndrome (DS), but in some instance STP is also used for treating refractory seizures in developmental and epileptic encephalopathies (DEEs) other than DS. The present study was conducted to evaluate the long‐term effectiveness and tolerability of STP in DS and non-Dravet DEEs._x000D_
Methods: In this retrospective observational study, data were collected for all DEE patients who have been prescribed adjunctive STP at Hospital Ruber Internacional (Madrid) from January 2000 to June 2020. Main outcomes that were evaluated were retention rate; responder rate (responders being defined as patients with ≥50% reduction in total seizure frequency relative to baseline); seizure freedom rate; responder rate for status epilepticus; rate of adverse events (AEs) and individual AEs. Outcomes are reported overall, and for Dravet and other refractory DEEs.

Results: Data were collected for 55 patients with a median age of 13.0 years (interquartile range [IQR] = 8.0-19.5 years). Thirty-three patients had Dravet syndrome and 22 had other refractory DEEs. Most of the DEE patients were diagnosed with undefined epileptic encephalopathy, but some had Lennox-Gastaut syndrome or Doose syndrome. Median age of epilepsy onset was younger in the Dravet patients (5.0 months) than non-Dravet (12.5 months). Median duration of treatment with STP was 28.0 months (IQR = 5.5-62.0 months) and was longer in the Dravet group (44.0 months) than non-Dravet (10.5 months, rank sum test, P=0.002). At 12 months, retention rate was 70.9% overall (39/55), 78.8% in the Dravet group (26/33) and 59.1% in non-Dravet (13/22). At 12 months, the responder rate was 27.3% overall (15/55), 30.3% in the Dravet group (10/33) and 22.7% in non-Dravet (5/22). No patients were seizure-free for 12 months; however, 60.0% (18/30) were free of status epilepticus at final visit, and this was significantly higher in the Dravet group (15/21, 71.4%) than non-Dravet (3/9, 33.3%, Fisher’s exact test, P=0.002). There were no statistically significant differences between groups on seizure outcomes. Adverse events were reported in 54.5% of patients (30/55), most commonly somnolence, anorexia, and irritability. In secondary analyses using multivariable models adjusted for age, sex and clinical group, both retention rate and responder rate were associated with the presence of bilateral tonic-clonic seizures.

Conclusions: In this population of patients with DEEs, STP demonstrated comparable and significant improvements in outcomes in both patients with Dravet syndrome and other DEEs, with a marked responder rate for status epilepticus in patients with Dravet syndrome.

Funding: None