A Study to Investigate the Efficacy and Safety of Cannabidiol (GWP42003-P; CBD) as Adjunctive Treatment for Seizures Associated With Lennox-Gastaut Syndrome in Children and Adults

Etiology of participant's seizures was a progressive neurologic disease. Participants with tuberous sclerosis were not excluded from study participation, unless there was a progressive tumor.

Participant had an anoxic episode requiring resuscitation within 6 months of screening.

Participant had clinically significant unstable medical conditions other than epilepsy.

Participant had clinically relevant symptoms or a clinically significant illness in the 4 weeks prior to screening or randomization, other than epilepsy.

Participant was currently using or has in the past used recreational or medicinal cannabis, or synthetic cannabinoid based medications (including Sativex®) within the 3 months prior to study entry and was unwilling to abstain for the duration of the study.

Participant had any known or suspected hypersensitivity to cannabinoids or any of the excipients of the Investigational Medicinal Product (IMP), such as sesame oil.

Participant had been part of a clinical trial involving another IMP in the previous 6 months.

Participant had significantly impaired hepatic function at screening or randomization (Alanine aminotransferase \[ALT\] \>5 x upper limit of normal \[ULN\] or total bilirubin \[TBL\] \>2 x ULN) OR the ALT or Aspartate aminotransferase (AST) \>3 x ULN and (TBL \>2 x ULN or international normalized ratio \>1.5). This criterion can only be confirmed once the laboratory results are available; Participants randomized into the study who are later found not to meet this criterion should be withdrawn from the study.

Any history of suicidal behavior or any suicidal ideation of type 4 or 5 on the Columbia Suicide Severity Rating Scale in the last month or at screening.

Participant was taking more than 4 concurrent AEDs.

Participant was taking corticotropins in the 6 months prior to screening.

Participant was taking long-term systemic steroids (excluding inhaled medication for asthma treatment) or any other daily medication known to exacerbate epilepsy. An exception was made of prophylactic medication, for example, idiopathic nephrotic syndrome or asthma.

Participant was taking felbamate, and they had been taking it for less than 1 year prior to screening.

What this study is about