Adjunctive Use of Cannabidiol: A Joint Action to Patch Up Drug-Resistant Epilepsy

Adjunctive Transdermal Cannabidiol for Adults With Focal Epilepsy: A Randomized Clinical Trial O’Brien TJ, Berkovic SF, French JA, Messenheimer JA, Sebree TB, Bonn-Miller MO, Gutterman DL; STAR 1/STAR 2 Study Group. JAMA Netw Open. 2022;5(7):e2220189. doi:10.1001/jamanetworkopen.2022. 20189. Erratum in: JAMA Netw Open. 2022;5(8): e2228862. Erratum in: JAMA Netw Open. 2022;5(12):e2249107. PMID: 35802375; PMCID: PMC9270696 Importance: Cannabidiol has shown efficacy in randomized clinical trials for drug-resistant epilepsy in specific syndromes that predominantly affect children. However, high-level evidence for the efficacy and safety of cannabidiol in the most common form of drug-resistant epilepsy in adults, focal epilepsy, is lacking. Objective: To investigate the efficacy, safety, and tolerability of transdermally administered cannabidiol in adults with drug-resistant focal epilepsy. Design, Setting, and Participants: A randomized, double-blind, placebo-controlled, multicenter clinical trial at 14 epilepsy trial centers in Australia and New Zealand. Participants were adults with drug-resistant focal epilepsy receiving a stable regimen of up to 3 antiseizure medications. Data were analyzed from July 2017 to November 2018. Interventions: Eligible participants were randomized (1:1:1) to 195-mg or 390-mg transdermal cannabidiol or placebo twice daily for 12 weeks, after which they could enroll in an open-label extension study for up to 2 years. Main Outcomes and Measures: Seizure frequency was self-reported using a daily diary. The primary efficacy end point was the least squares mean difference in the log-transformed total seizure frequency per 28-day period, adjusted to a common baseline log seizure rate, during the 12-week treatment period. Results: A total of 188 patients (45% male [85 patients] and 54.8% female [103 patients]) with a mean (SD) age of 39.2 (12.78) years were randomized, treated, and analyzed (195-mg cannabidiol, 63 participants; 390-mg cannabidiol, 62 participants; placebo, 63 participants). At week 12 of the double-blind period, there was no difference in seizure frequency between placebo (mean [SD] 2.49 [1.31] seizures per 28 days) and 195-mg cannabidiol (mean [SD] 2.51 [1.15] seizures per 28 days; least squares mean difference, 0.014; 95% CI, −0.175 to 0.203; P = .89) or 390-mg cannabidiol (mean [SD] 2.59 [1.12] seizures per 28 days; least squares mean difference, 0.096; 95% CI, −0.093 to 0.285; P = .32). By month 6 of the open-label extension, 115 patients (60.8%) achieved a seizure reduction of at least 50%. Treatment-emergent adverse events occurred in 50.4% (63 of 125 participants) of the cannabidiol group vs 41.3% (26 of 63 participants) in the placebo group, with a treatment difference of 9.1% (95% CI, −6.0% to 23.6%), and occurred at similar rates in the cannabidiol groups. Few participants discontinued (7% [14 of 188 participants]), and most (98% [171 of 174 participants]) continued into the open-label extension. Conclusions and Relevance: Both doses of transdermal cannabidiol were well tolerated and safe. No significant difference in efficacy was observed between cannabidiol and placebo during the double-blind treatment period. The open-label extension demonstrated the long-term safety, tolerability, and acceptability of transdermal cannabidiol delivery. Trial registration: ACTRN12616000510448 (double-blind); ACTRN12616001455459 (open-label). Real World Data on Cannabidiol Treatment of Various Epilepsy Subtypes: A Retrospective, Multicenter Study Kühne F, Becker LL, Bast T, Bertsche A, Borggraefe I, Boßelmann CM, Fahrbach J, Hertzberg C, Herz NA, Hirsch M, Holtkamp M, Janello C, Kluger GJ, Kurlemann G, Lerche H, Makridis KL, von Podewils F, Pringsheim M, Schubert-Bast S, Schulz J, Schulze-Bonhage A, Steinbart D, Steinhoff BJ, Strzelczyk A, Syrbe S, De Vries H, Wagner C, Wagner J, Wilken B, Prager C, Klotz KA, Kaindl AM. Epilepsia Open. 2023. doi:10.1002/epi4.12699. Epub ahead of print. PMID: 36693811 Objective: Cannabidiol (CBD) is approved for treatment of Dravet syndrome (DS), Lennox-Gastaut syndrome (LGS), and tuberous sclerosis complex (TSC). Several studies suggest anti-seizure effects also beyond these three epilepsy syndromes. Methods: In a retrospective multi-center study, we analyzed the efficacy and tolerability of CBD in patients with epilepsy at 16 epilepsy centers. Results: The study cohort comprised 311 patients with epilepsy with a median age of 11.3 (0-72) years (235 children and adolescents, 76 adults). Therapy with CBD was off-label in 91.3% of cases due to age, epilepsy subtype, lack of adjunct therapy with clobazam, and/or higher dose applied. CBD titration regimens were slower than recommended, with good tolerability of higher doses particularly in children. Of all patients, 36.9% experienced a reduction in seizure frequency of >50%, independent of their epilepsy subtype or clobazam co-medication. The median observation period was 15.8 months. About one third of all patients discontinued therapy within the observation period due to adverse effects or lack of efficacy. Adverse effects were reported frequently (46.9%). Significance: Our study highlights that CBD has an anti-seizure effect comparable to other anti-seizure medications with a positive safety profile independent of the epilepsy subtype. Comedication with clobazam was not associated with a better outcome. Higher doses to achieve seizure frequency reduction were safe, particularly in children. These findings call for further trials for an extended approval of CBD for other epilepsy subtypes and for children <2 years of age.