Safety of Diazepam Nasal Spray in Pediatric Patients With Developmental Epileptic Encephalopathies: Results From a Long-term Phase 3 Safety Study

Pediatric developmental epileptic encephalopathies are often refractory to treatment despite stable antiseizure therapy. The safety profile of diazepam nasal spray (Valtoco) as rescue therapy for seizure clusters was described in a long-term safety study. This post hoc analysis assessed safety and effectiveness within a subpopulation of patients with developmental epileptic encephalopathies. Of 163 treated patients, 64 were diagnosed with ≥1 pediatric developmental epileptic encephalopathy. Among the most common developmental epileptic encephalopathies were Rett syndrome (n = 16), Lennox-Gastaut syndrome (n = 9), and Dravet syndrome (n = 7). In the broad pediatric developmental epileptic encephalopathy group, 10.6% of seizure clusters were treated with a second dose, with similar proportions in the 3 individual encephalopathies. Across groups, treatment-emergent adverse event rates ranged from 66.7% to 100%. Only epistaxis (n = 2) was treatment-related and reported in >1 patient. In this long-term safety analysis in patients with developmental epileptic encephalopathies, diazepam nasal spray demonstrated a consistent safety profile, supporting its use in these hard-to-treat patients (ClinicalTrials.gov NCT02721069).