UK-based GW Pharmaceuticals (GWPH) announced that a Phase 2a proof of concept study of a pipeline compound GWP42006 in adult patients with focal seizures did not meet its primary endpoint. The Phase 2a study evaluated the efficacy and safety of GWP42006, which features cannabidivarin (CBDV) as the primary cannabinoid molecule. The drug was meant as an add-on treatment for adults with inadequately controlled focal seizures. Focal seizures are partial seizures that happen when this neural disturbance remains in a limited area of the brain.
The study was conducted primarily in Eastern Europe. The top-line results in both the drug and the placebo showed a drop of approximately 40% in the number of seizures experienced. This was a much higher response from the placebo than had been expected.
GW Pharmaceutical said in a statement that the drug was generally well tolerated. Still, the company stated, “More patients in the active group (73 percent) experienced treatment-emergent adverse events compared to the placebo group (48 percent). A majority of the GWP42006 patients experienced adverse events of mild or moderate severity.
The compound has shown anti-epileptic properties across a range of in vitro and in vivo models of epilepsy. GW Pharmaceuticals said it would continue to look for other opportunities for the compound.
In parallel with this study, GWP42006 was also being evaluated in both general and syndromic pre-clinical models of Autism Spectrum Disorder (ASD) yielding promising signals on cognitive and social endpoints as well as repetitive behavior. The company said in a statement that it would “continue to advance various clinical initiatives within the field of ASD, including a physician-led expanded access IND in 10 patients with autism as well as both open-label and Phase 2 placebo-controlled trials in Rett syndrome, a condition for which GWP42006 has received Orphan Drug Designation from the FDA.” Open-label data from the expanded access IND are expected later in 2018.
“Whilst the results of this adult focal seizure study for GWP42006 are disappointing, we remain committed to advancing this pipeline compound to address unmet needs in the field of autism spectrum disorders, in which a promising body of pre-clinical data has already been generated, as well as continuing to explore the product’s potential within the field of epilepsy,” said Justin Gover, GW’s Chief Executive Officer.
Gover said that Epidiolex remained the top priority for the year. The stock fell almost 6% in after-hours trading to approximately $124.