Abstracts

Rationale: Open-label studies in refractory epilepsy patients suggest that treatment with pharmaceutical grade Cannabidiol (CBD) improves seizure control. Seizure severity is an important factor that impacts quality of life. The Chalfont Seizure Severity Scale is a validated tool used to assess the disruptive aspects of seizures as a measure of severity. Total scores are obtained and can be further broken down by seizure type. This study evaluates the effects of pharmaceutical grade CBD (Epidiolex) on seizure severity via the Chalfont Seizure Severity Scale. Methods: 81 patients (42 children; 39 adults) with medically refractory Video EEG-confirmed epilepsy who failed at least 4 antiepileptic drugs and who suffered on average 4 seizures/month were treated with CBD in this state-sponsored, open-label, expanded access program. Seizure severity was measured by the Chalfont Seizure Severity Scale. Total scores as well as scores for the most frequent seizure type (Chalfont Seizure Type I) were obtained on each patient during pretreatment baseline, 3 and 6 months visits. Change and percent change of time weighted average value (TMV) in the Chalfont Epilepsy Severity Scale Total score and Seizure Type 1 score were analyzed at 3 months (28 children; 30 adults) and 6 months (21 children; 26 adults) compared to pre-treatment baseline. Scores were then compared between responders (>50% decrease in seizure frequency) and nonresponders ( < 50% decrease is seizure frequency) and in adults, children, and all patients using standard statistical measures. Results: The mean change in Chalfont total score from baseline to 3 months was 31.8 41.6 (p < 0.0001) and from baseline to 6 months was 30.4 SD 45.9 (p < 0.0001) in all patients. At 3 months, there was a significant decrease (p < 0.03) in percent change of total scores in responders (n=38, mean score 32.6 59.1) vs. nonresponders (n=19, mean score 21.9 59.1) that did not persist at 6 months (p>0.05). At 3 months, Chalfont Total score was significantly decreased in adults (mean score 46.4 50.6; p < 0.0001) vs. children (mean score 16.7 21.4; p < 0.0003); at 6 months Chalfont scores were decreased in adults (mean score 39.3 57.99; p < 0.002) and children (mean score 19.3 20.3; p < 0.0003). The mean change in Chalfont Seizure Type I score (most frequent seizure type for all patients) from baseline to 3 months was 11.1 15.7 (p < 0.0001) and from baseline to 6 months was 12 18 (p < 0.0001) in all patients; however change in scores only remained significant for children and not adults at 6 months. At 3 months, the Chalfont Seizure Type 1 percent change decrease in responders (n=37, mean score 31.6 57.2) vs. nonresponders (n=19, mean score 22.4 57.2) in all patients was significant (p < 0.05) but did not remain significant at 6 months (p>0.2). There was no significant difference of decrease or percentage decrease of Chalfont Seizure Type 1 score between adults and children (Table 1). Conclusions: The findings in this state-sponsored, expanded access, open-label study suggest that treatment with pharmaceutical grade CBD improves seizure severity in adults and children. Funding: State of Alabama