Rare Disease Report

Cannabinoid Product Shows Positive Phase 3 Trial Results

JUNE 27, 2016
Andrew Black
Last week, we reported GW Pharmaceuticals announced a 4th orphan indication for Epidiolex – infantile spasms – will be studied in a pivotal Phase 3 study beginning in the 4th quarter of 2016. This came when the FDA has granted Epidiolex with an orphan designation for infantile spasms.
Epidiolex is GW Pharmaceutical’s lead cannabinoid product. The drug is already being developed in 3 other orphan indications – Dravet syndrome, Lennox-Gastaut syndrome (LGS) and Tuberous Sclerosis Complex (TSC).
With positive results with the Phase 3 Trials with patients with Dravet syndrome, GW hoped to see positive results with Epidolex for patients the other orphan destinations. They did.
In previous research and trials, cannabidiol has reduced patient seizures for a variety of different diseases. Last year, we reported on the cannabinoid’s ability to decrease seizures by 54% in a 12 week study involving 137 Dravet syndrome and LGS patients.
This week, the company announced positive results from their phase 3 clinical trials of Epidiolex for the treatment of LGS, a rare and severe form of childhood-onset epilepsy. The drug achieved the primary endpoint of a mass reduction in the monthly frequency of drop seizures in a 14-week span.

Clinical Trials

Patients ages ranged from 2-55 with a confirmed diagnosis of LGS and on one or more anti-epileptic drugs (AEDs) were eligible for participation in the trials. The trial randomized 171 patients into two arms, where Epidiolex 20mg/kg/day (n=86) or a placebo (n=85) was added to current AED treatment.
The endpoint of the trial was the comparison of Epidiolex and the placebo by statistically viewing the percentage change of the monthly frequency of drop seizures during the 14-week trial treatment period (2-week dose escalation, period followed by 12 weeks of maintenance). This was compared to the 4-week baseline period before randomization.
Patient’s seizures were categorized by the following:
  • Atonic (sudden loss of muscle tone, so that the child goes limp and falls to the ground)
  • Tonic (loss of consciousness and violent muscle contractions)
  • Tonic-clonic seizures (rapidly alternating contraction and relaxation of a muscle)
Overall, Epidiolex achieved a median reduction in monthly drop seizures of 44% compared with a reduction of 22% in patients receiving placebo, the difference between these two were very significant P0.0135.
The difference between Epidiolex and placebo became apparent during the first month of treatment during the trial and was sustained during the entire treatment period.
Along with the first phase 3 trials of Epidiolex for treating LGS, GW is now conducting a second phase 3 trial of Epidiolex for the treatment of LGS which includes 225 enrolled patients. The second trials contain three treatment arms: Epidiolex 20mg/kg/day, 10mg/kg/day and placebo.
GW hopes for significant results from the second phase 3 trials.

About Lennox-Gastaut syndrome (LGS)

 Lennox-Gastaut syndrome (LGS) is a severe childhood epileptic encephalopathy that is estimated to affect 15 per 100,000 persons. The syndrome is associated with multiple seizure types, including tonic, atonic, tonic clonic, myoclonic, and absence seizures. Some patients may also experience focal or partial seizures.

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