BackgroundThere is a paucity of high-quality evidence of the efficacy and safety of cannabis-based medicinal products in treatment of treatment-resistant epilepsy (TRE) in children.MethodsA case series of children (<18 years old) with TRE from the UK Medical Cannabis Registry was analyzed. Primary outcomes were ≥50% reduction in seizure frequency, changes in the Impact of Pediatric Epilepsy Score (IPES), and incidence of adverse events.ResultsThirty-five patients were included in the analysis. Patients were prescribed during their treatment with the following: CBD isolate oils (n= 19), CBD broad-spectrum oils (n= 17), and CBD/Δ9-THC combination therapy (n= 17). Twenty-three (65.7%) patients achieved a ≥50% reduction in seizure frequency. 94.1% (n= 16) of patients treated with CBD and Δ9-THC observed a ≥50% reduction in seizure frequency compared to 31.6% (n= 6) and 17.6% (n= 3) of patients treated with CBD isolates and broad-spectrum CBD products, respectively (p< 0.001). Twenty-six (74.3%) adverse events were reported by 16 patients (45.7%). The majority of these were mild (n= 12; 34.2%) and moderate (n= 10; 28.6%).ConclusionThe results of this study demonstrate a positive signal of improved seizure frequency in children treated with Cannabis-based medicinal products (CBMPs) for TRE. Moreover, the results suggest that CBMPs are well-tolerated in the short term. The limitations mean causation cannot be determined in this open-label, case series.