Long-Term CBD Use Tied to Reduced Seizures in Treatment-Resistant Epilepsy

Patients with treatment-resistant epilepsy (TRE) who received cannabidiol (CBD) experienced seizure reduction with long-term use, according to study results presented at the 2024 American Academy of Neurology (AAN) annual meeting, held from April 13 to 18, 2024, in Denver, Colorado.

With the lack of information regarding the long-term use of CBD in patients with TRE, researchers conducted a study to establish long-term results for the safety and efficacy of CBD in this patient population.

This 4-year study was conducted as part of the United States Expanded Access Program (EAP). Study participants received plant-derived, highly purified CBD at 100 mg/mL as an oral solution, increasing by 2 to 10 mg/kg a day to a tolerance. The maximum dosage of CBD was 25 to 50 mg/kg per day.

The researchers calculated the change from baseline in the median monthly frequency of seizures and the responder rates (RR) at 12-week intervals through the end of the study. 

A total of 892 patients were included in the safety population, with 193 (22%) adult patients (mean age, 27.3). The median number of antiseizure medications (ASMs) prescribed to a patient was 3, ranging from 1 to 7. The most common ASMs were clobazam (37%), levetiracetam (34%), and lamotrigine (33%). 

Patients had a median CBD exposure of 733 days. The greatest CBD dose was a median of 25 mg/kg per day.

In an efficacy analysis of 182 patients, the researchers found that the median frequency of convulsive seizures was 22 and total seizures was 40. Patients who received CBD treatment showed a median reduction of convulsive seizures (45%-64%) and total seizures (41%-63%) from baseline.

The RR for convulsive seizures through week 144 of the study period showed a sustained response of:

• 49% to 64% of patients experiencing at least a 50% reduction,
• 27% to 39% of patients experiencing at least 75% reduction, and
• 7% to 16% of patients experiencing a 100% reduction.

Total seizure RR demonstrated reductions of at least 75% in 25% to 38% of patients across the study period. 

Adverse events (AEs) were reported in 92% of participants, with serious AEs reported among 39% of patients. The most common treatment-related AE (≥20%) was diarrhea (49%), followed by somnolence (24%). Patients also reported abnormal liver function, with increased alanine transaminase (ALT; 5%), increased aspartate transaminase (AST; 5%), and abnormal liver function tests (5%).

A total of 8% of participants discontinued the study due to an AE. There were 2 deaths that occurred within the study period and both were not attributed to the study medication.

“Add-on CBD was associated with seizure reduction through 144 weeks with an acceptable safety profile in adult patients with TRE, supporting its long-term use in a real-world setting,” the researchers concluded.

 Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.