Epidiolex, the only plant-derived cannabis drug approved by the U.S. Food and Drug Administration, is no longer considered a controlled substance, providing a boost to its manufacturer’s stock price.

GW Pharmaceuticals, a biopharmaceutical company based in London, saw its stock go up 5.9% on Tuesday, one day after the U.S. Drug Enforcement Administration said it would no longer classify Epidiolex as a Schedule 5 drug under the federal Controlled Substance Act.

Epidiolex is used to treat rare forms of epilepsy.

The DEA’s announcement lowers physician barriers to prescribing Epidiolex because they won’t have to notify the agency when prescribing it.

GW said it will now begin “implementing these changes at the state level” and through its distribution network.

The expansion comes two years after the DEA first took Epidiolex off the most-restrictive class of controlled substances.

That decision, issued months after the FDA approved the drug for treating certain types of epilepsy, was the first time the DEA removed any type of cannabis from Schedule 1.

The company’s U.S. subsidiary is Greenwich Biosciences.

GW Pharma trades on the Nasdaq as GWPH.

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