A cannabis-based medicine could help the world’s 50 million epileptics control their seizures after a British drugmaker today began putting a potential treatment through human clinical trials.

GW Pharmaceuticals, which already uses cannabis to make Sativex for MS sufferers, has spent five years carrying out pre-clinical research on whether a cannabis-derived compound could treat epileptics’ seizures, with fewer side effects than current drugs.

About a third of epileptics take no medication, either because existing treatments don’t control their seizures or because they can’t tolerate the side effects.

But positive results from GW’s research mean it is putting its potential new drug, dubbed GWP42006, through Phase 1 human trials. The drugmaker grows genetically-cloned marijuana plants for the medicine in secret locations in England.

The trials announcement is “a significant milestone in the development of this novel product candidate,” said Stephen Wright, GW’s director of research.