GW Pharmaceuticals (NASDAQ:GWPH) has been granted approval by the European Commission to sell its star drug Epidyolex in the European Union (EU). The company announced that the Commission, the EU's pharmaceutical regulator, has authorized Epidyolex for aiding in the treatment of seizures in children who suffer from one of two forms of epilepsy.

The medication, which is known as Epidiolex in the United States, was approved by the U.S. Food and Drug Administration in June 2018. It has become a hot product for the company, bringing in almost $102 million in net sales in the first half of this year. It also greatly helped the company reduce its operating loss.

A person in lab coat with a stethoscope around their neck holding a cannabis leaf and cannabis oil and a bud.

Image source: Getty Images.

Epidiolex has been prescribed by more than 2,500 doctors, according to the company, and has been received by over 12,000 patients. The company says that its patients tend to stay on the treatment.

Epidiolex is the first FDA-approved drug based on cannabidiol (CBD), the substance found inside cannabis that does not get a user high (that would be tetrahydrocannabinol, or THC). For this reason, GW Pharmaceuticals is considered to be a marijuana stock.

In the press release heralding the news, the company wrote that "[t]his approval is the culmination of many years of dedication and collaboration between GW, physicians and the epilepsy community. We believe patients and physicians deserve access to rigorously tested and evaluated cannabis-based medicines, manufactured to the highest standards and approved by medicines regulators."

Epidiolex from GW Pharmaceuticals.

Image source: GW Pharmaceuticals.

The regulator's nod gives GW Pharmaceuticals the green light to market and sell Epidyolex in all 28 EU countries, plus Norway, Iceland, and tiny Liechtenstein. It will initially roll out the drug in France, Germany, and perhaps the U.K., with Spain and Italy following at some point in 2020. The company is estimating that the total EU market for Epidyolex is roughly "a quarter to a third" of its U.S. counterpart.

Epidyolex is used as a supplemental medicine to treat seizures in patients afflicted with either Lennox-Gastaut syndrome or Dravet syndrome. GW Pharmaceuticals claims its drug is "the first in a new class of epilepsy medicines and the first and only [EU]-approved CBD medicine to treat two severe and life-threatening forms of childhood-onset epilepsy."