The world’s only widely approved medical CBD formula performed weakly in a key clinical trial in Japan, the maker of the drug reported.
Epidiolex, an oral solution for treating rare forms of epilepsy in children, “did not achieve its primary goal of a significant reduction in seizure frequency” in a Phase 3 trial, according to Jazz Pharmaceuticals, the parent company of GW Pharmaceuticals, which makes the drug.
Phase 3 trials are critical in the four-phase drug development process because they provide the most comprehensive data on how well a drug works, and its safety profile, which is used by regulatory bodies such as the Food & Drug Administration (FDA) in the U.S., the European Medicines Agency (EMA) and the UK’s Healthcare Products Regulatory Agency (MHRA) to decide whether to approve the drug for public use.
‘No new safety issues’
Despite the weak performance in reducing seizures, Jazz said the trials uncovered no new safety issues, and recorded “improvements” in unspecified “other areas.”
Rob Iannone, the company’s executive vice president, global head of research and development, said Jazz remains confident in the overall clinical profile of Epidiolex, which he said has been established in more than 900 patients in five other Phase 3 clinical trials. He said the company will continue to work with Japanese regulatory authorities regarding a “potential” new drug application.
“We recognize the significant unmet need for patients in Japan living with rare epilepsies,” Iannone said.
The trial in Japan, which is ongoing, is focused on measuring how much seizure frequency changes over a treatment period of up to 16 weeks in 62 children aged 1 to 18 years old.
Japanese officials approved Epidiolex for hospital-based clinical trials in 2019, exempting the drug from the country’s Cannabis Control Act, which bans cannabis compounds generally.
Approval history
Epidiolex, a high CBD, no THC formula, first won general approval in 2018 from the FDA, which later approved the drug in 2020 as a treatment specifically for seizures associated with Lennox-Gastaut Syndrome, Dravet Syndrome and Tuberous Sclerosis Complex. It was approved by the EMA in Europe and the MHRA in the UK in 2019. (The drug goes by the alternative spelling “Epidyolex” in Europe and the UK.) Canada’s federal health regulator, Health Canada, approved the medicine late last year.
GW Pharmaceuticals is considered to be the biggest medical cannabinoid company in the world, having developed its products under strict regulations for medicine in the markets where it is present. It was acquired by Ireland-based Jazz in 2021.
Sales of Epidiolex reached $845.5 million in 2023, an increase of 15% from the previous year. Jazz Pharmaceuticals, whose shares are traded on the NASDAQ Global Market, had total revenues of $3.8 billion in 2023.