- GW Pharmaceuticals saw its stock soar on Monday after announcing its cannabidiol drug Epidiolex helped reduce the frequency of seizures among patients with a rare form of childhood-onset epilepsy, hitting its primary endpoint in the third successful Phase 3 study of the drug.
- When Epidiolex was added to the existing treatment regimen of patients with Lennox-Gastaut Syndrome (LGS), the rate of monthly drop seizures fell by 42% at the highest dose, compared to only 17% for those on the placebo.
- A previous Phase 3 trial in LGS also read out positive in June, and a March study in patients with Dravet Syndrome also produced positive results. GW Pharma plans to submit Epidiolex for U.S. approval sometime in the first half of 2017.
Some children can grow out of infantile seizures. For others, epilepsy is a life-long, debilitating and damaging disease that robs patients of the chance to live independently. Lennox-Gastaut Syndrome is a rare form of childhood-onset epilepsy that is difficult to control. Existing treatments include antiepileptic drugs, corticosteroids, and surgery, and aren't always effective.
GW Pharma's Epidiolex is one of only a few drugs approved or in the pipeline for LGS.
Novartis and Eisai's Banzel/Inovelon (rufinamide) is approved as adjunctive treatment of seizures associated with Lennox-Gastaut Syndrome. Eisai's Fycompa (perampanel) is in a Phase 3 study for this indication as well, but the drug carries a black box warning and is a Schedule III controlled substance. Zogenix is developing ZX008, a low-dose form of the discredited weight-loss drug fenfluramine, testing the drug in a Phase 2 study as an add-on therapy for LGS.
In an attempt to bridge the treatment gap, GW Pharmaceuticals developed Epidiolex, a liquid form of pure, plant-derived cannabidiol. Results from the two Phase 3 trials in Lennox-Gastaut syndrome have shown that the bold move has been borne out in the data.
“The announcement of a second set of positive results with Epidiolex is exciting as they offer much needed hope for patients and their families living with this debilitating condition where new treatment options are desperately needed," said Christina SanInocencio, executive director of the Lennox-Gastaut Syndrome Foundation.
Epidiolex has also been successful in a Phase 3 trial among patients with Dravet syndrome, also a rare form of epilepsy. Following a July 2016 conversation with the FDA, GW Pharmaceuticals plans to submit a single NDA for both Lennox-Gastaut syndrome and Dravet syndrome during the first half of 2017, rather than waiting for data from a second Dravet syndrome study.
Epidiolex is also in a Phase 3 trial in tuberous sclerosis complex and GW plans to start a Phase 3 trial in infantile spasms in the fourth quarter of 2016.