To evaluate the long-term efficacy (up to 192 weeks) and safety (up to 233 weeks) of add-on CBD in patients with TSC in the EAP final analysis.

Patients received plant-derived highly purified CBD (100 mg/mL oral solution) increasing from 2–10 mg/kg/d to tolerance or maximum 25–50 mg/kg/d dose, depending on the study site. Efficacy: percentage change from baseline in convulsive, focal, and total seizure frequency and responder rates across visit windows (12-week windows through 192 weeks). Safety: adverse events (AEs).

Of 892 patients in the safety analysis set, 34 patients had TSC. Of those with TSC, 8 (24%) patients withdrew. Mean (range) age: 12.4 (1.8–31.2) years.  Median (range) concomitant antiepileptic drugs (AEDs): 3 (1–7). Most common AEDs: clobazam (20 [59%]), lamotrigine (14 [41%]), levetiracetam (11 [32%]), and valproate (6 [18%]). Top median (Q1, Q3) CBD dose: 40 (25, 50) mg/kg/day. Baseline median (Q1, Q3) monthly seizure frequency: 46 (18, 76) for convulsive, 37 (24, 84) for focal, and 64 (31, 148) for total seizures. Median percentage reduction in seizure frequency during the first 48 weeks ranged from 48–55% for convulsive, 61–75% for focal, and 44–56% for total seizures; and the overall pattern of response was maintained through 192 weeks. Similarly, responder rates (≥50%) were maintained through 192 weeks for all seizure types. AEs were reported by 94% of patients and serious AEs by 47%; there were no deaths. Most common AEs: somnolence (32%), diarrhea (29%), convulsion (18%), and vomiting (18%). Liver-related AEs occurred in 1 patient (3%).

Add-on CBD resulted in sustained seizure reduction in patients with TSC for up to 192 weeks with an acceptable safety profile.

Funding: GW Research Ltd