Image source: GW Pharmaceuticals.

Building on its success in treating a rare form of epilepsy known as Dravet syndrome earlier this year, marijuana has now shown that it can be used to reduce seizures in patients suffering from Lennox-Gastaut syndrome, or LGS, too. Cannabis drug researcher GW Pharmaceuticals (NASDAQ:GWPH) reported results from a phase 3 study today demonstrating that using its marijuana drug Epidiolex can lower the rate of seizure in LGS patients by 44%.

Cannabis curbs epilepsy

GW Pharmaceuticals Epidiolex is a purified formulation of CBD, a non-psychoactive chemical cannabinoid found in cannabis. 

Earlier this year, the company reported that using Epidiolex can lower the number of convulsive seizures in Dravet syndrome patients. In that study, patients were given Epidiolex or a placebo alongside their current antiepileptic drugs. Patients receiving Epidiolex experienced 39% fewer seizures versus their baseline, while patients receiving placebo saw their number of monthly seizures fall by 11%.

Today, GW Pharmaceuticals reports that Epidiolex can lower the number of drop seizures in LGS patients, too. 

In a phase 3 study, patients who got Epidiolex added to their treatment regimen had 44% fewer drop seizures per month than they had prior to treatment. A group given placebo instead of Epidiolex saw their rate of drop seizure decline 22% from baseline.

These findings are especially intriguing because these patients are among the most difficult epilepsy patients to treat. Patients in the company's Dravet syndrome trial had previously taken and failed an average of more than four other anti-epileptic therapies, and in the LGS trial, the average patient had previously failed an average of six prior anti-epileptic drugs.

In both trials, safety appears to be OK, too. 

In the Dravet syndrome trial, eight of 61 patients taking Epidiolex discontinued the trial because of adverse events, and in the LGS trial, 12 of 86 patients stopped taking Epidiolex because of adverse events. That suggests the vast majority of patients found Epidiolex to be beneficial. That thinking is reinforced by the fact that 100% of the remaining patients in the LGS trial enrolled in a follow-on study so they could continue to receive Epidiolex.

Image source: GW Pharmaceuticals.

More results are coming

In addition to the two trials that have already wrapped up, GW Pharmaceuticals expects to report results from two additional trials in the coming months.

A second trial in LGS is expected to have data available by the end of the third quarter, and results from a second trial in Dravet syndrome should be available early next year.

Assuming those studies confirm the data that's already been released, GW Pharmaceuticals could file for FDA approval of Epidiolex in the first half of 2017. An early 2017 filing could clear the way for approval shortly thereafter, because Epidiolex is fast-tracked by the FDA for use in Dravet syndrome. If the FDA determines Epidiolex is a major treatment advance, fast-track status could result in an accelerated review by the agency, reducing the FDA approval timeline from 10 months to six months. 

Looking forward

A win for Epidiolex in epilepsy is important for both patients and GW Pharmaceuticals. Patients need new treatment options, and a commercially approved therapy in the U.S. could go a long way toward firming up GW Pharmaceuticals' financials. The company currently generates only a few million dollars in sales per quarter, yet its marijuana research program costs it about $37 million per quarter. 

There's no guarantee the remaining trials will pan out, or that if the FDA approves Epidiolex, it will be a top seller, but these results suggest that many of the thousands of people suffering from these rare forms of epilepsy could benefit from Epidiolex. For that reason alone, it's worth cheering for its success.