Today shares of GW Pharmaceuticals plc (GWPH) are up for more than 124% after the company announced positive phase 3 results for a trial using its drug Epidiolex. The drug was able to meet the primary endpoint of the study, reduction of seizures compared to a placebo compound over the course of the entire trial — P-value, p = 0.01. Patients in the trial that were recruited have a rare disorder known as Dravet Syndrome. 

Such a positive result creates excitement as there are currently no FDA approved drugs for Dravet Syndrome. The FDA was happy to give Epidiolex both Orphan Drug Designation and Fast Track Designation. The latter provides benefits such as tax benefits, and seven years of market exclusivity. The latter provides quicker review time compared to other submitted drugs. 

These results are remarkable because Dravet Syndrome is the most complicated form of epilepsy to treat. It is a type of epilepsy children are born with that leads to seizures either due to hot temperatures or fevers occurring. Epidiolex not only reduced seizure outcome in the trial, but was also safe and tolerable for patients with no side effects.

The trial recruited a total of 120 patients who were randomized into two different arms of the trial. One arm was Epidiolex 20 mg/kg/day, and the other arm was a placebo drug. Though both arms had current anti-epileptic drugs — AED — added with their regimens. Patients in the past had been on 4 or more AED. With the Epidiolex and placebo treatments these patients only needed 3 AED. 

GW Pharmaceuticals is now in the process of having a pre-NDA meeting with the FDA to discuss a proposal for a regulatory submission for Epidiolex in patients with Dravet Syndrome. The company also has other trials that are expected to read out results. One trial that is expected to be read out is two phase 3 trials using Epidiolex in patients with Lennox-Gastaut Syndrome and second pivotal trial using Epidiolex for Dravet Syndrome in phase 3.