A pharmaceutical grade formulation of cannabidiol (CBD) has been approved for the treatment of Dravet syndrome and Lennox-Gastaut syndrome; however, this formulation is not yet available to patients outside the USA. In addition, CBD is thought to have broad anti-seizure properties that may be beneficial for other types of intractable epilepsy.The aim of this study was to evaluate the efficacy, safety and tolerability of artisanal medical CBD oil in patients with developmental and epileptic encephalopathy (DEE) at the tertiary epilepsy center of Bambino Gesù Children's Hospital in Rome, Italy.This was a single-center, prospective, open-label study. Patients aged from 1 to 18 years with DEE and seizures refractory to appropriate antiepileptic drugs (AEDs) and other alternative treatments (i.e., vagal nerve stimulator and ketogenic diet) were included. Crystalline extract CBD powder (98-99% pure) in an oil artisanal formulation was added to the baseline AED regimen at a dosage of 2-5 mg/kg/day divided for twice-daily administration, then up-titrated until intolerance or a maximum dosage of 25 mg/kg/day was reached. Patients were treated for at least 6 months. Efficacy, safety and tolerability of CBD treatment were assessed through the evaluation of seizure frequency and reports of adverse effects.Twenty-nine patients were enrolled in this study (41.4% male). The mean duration of exposure to artisanal CBD was 11.2 months [range 6-25 months; standard deviation (SD) ± 4.4 months]. Mean age at study enrollment was 9.3 years (range 1.9-16.3 years; SD ± 4.7 years). Eleven out of 29 patients (37.9%) had a ≥ 50% improvement in seizure frequency; one patient became seizure free. None of the patients reported worsening seizure frequency; however, 18 patients (62.1%) experienced no beneficial effect regarding seizure frequency. Adverse effects were reported in seven patients (24.14%), most commonly somnolence, decreased appetite and diarrhea. Adverse events were mild and transient, and no dose modification of CBD or other AEDs was required.These data suggest that CBD may have beneficial effects in patients with DEE and an acceptable safety profile. Placebo-controlled randomized trials should be conducted to formally assess the safety and efficacy of CBD in patients with DEE.
