GW Pharmaceuticals and its subsidiary Greenwich Biosciences are gearing up to launch Epidiolex in the US after drug enforcement officials re-classified the cannabis-based medicine to the lowest restriction.

Epidiolex contains cannabidiol (CBD), a chemical component of the cannabis sativa plant, more commonly known as marijuana. CBD does not cause intoxication or euphoria that comes from tetrahydrocannabinol (THC), the primary psychoactive component of the drug.

The US Food and Drug Administration approved use of Epidiolex back in June to treat seizures associated with Lennox-Gastaut Syndrome or Dravet Syndrome, two rare, severe and notoriously difficult-to-treat childhood-onset epilepsies.

Now, clearing the final hurdle to market, the medicine has been reclassified by the Drug Enforcement Administration from Schedule I to Schedule V, thereby legally allowing its sale.

“We are pleased that the DEA has placed Epidiolex in the lowest restriction Schedule, because it will help ensure that patients with LGS and Dravet syndrome, two of the most debilitating forms of epilepsy, can access this important new treatment option through their physicians,” said Justin Gover, GW’s chief executive.

“With this final step in the regulatory process completed, we are working hard to make Epidiolex available within the next six weeks as we know there is excitement for a standardised version of cannabidiol that has undergone the rigor of controlled clinical trials and been approved by the FDA.”

The Epilepsy Foundation noted that people with epilepsy who are unable to obtain seizure control with existing treatments are at a higher risk of accident, injury, hospitalisation, and even death, and that the rescheduling of Epidiolex “is a tremendous milestone for some of these most vulnerable individuals who now may have access and hope of gaining better seizure control.”

The companies said they expect Epidiolex to be available in the US within six weeks.