GW cannabis drug succeeds in epilepsy trial, shares leap

An experimental cannabis-based drug has successfully treated children with a rare form of severe epilepsy in a keenly anticipated clinical trial, sending shares in its maker GW Pharmaceuticals 68 percent higher on Monday.

The study of GW's Epidiolex in Dravet syndrome is the first of four final-stage Phase III epilepsy trials that the drugmaker hopes will confirm the therapeutic benefits of cannabinoids, the active ingredients found in cannabis.

GW said the 120-patient trial showed patients taking Epidiolex achieved a median reduction in monthly convulsive seizures of 39 percent compared with a reduction on placebo of 13 percent, which was highly statistically significant.

In light of this positive data, Chief Executive Justin Gover said the company would now request a meeting with the U.S. Food and Drug Administration (FDA) to discuss its plans to seek regulatory approval for treating this particular form of epilepsy.

There are currently no FDA-approved therapies for Dravet syndrome.

GW was founded in 1998 with the aim of capitalizing on the medical benefits of cannabis, while purifying the active ingredients so as to avoid psychoactive effects.

Its multiple sclerosis treatment Sativex, which is distributed by marketing partners, is already has regulatory approval in more than 20 countries, although not the United States.

Epidiolex, however, is commercially more significant since GW retains full control of the product and the company has also geared the medicine's development to the big U.S. marketplace.

Optimism about the new drug's prospects has been building following positive feedback from “compassionate access” programs involving hundreds of American children, but the Phase III program is the make-or-break hurdle.