Clinical trial of CBD medicine to start in Japan

Reuters file photo
Cannabis plants grow inside a factory hothouse in Portugal in April 2019.

The Japanese arm of U.K. firm GW Pharmaceuticals plans to start clinical trials as early as this month of a drug containing cannabidiol (CBD), a substance derived from cannabis that is not currently legal for use in medicine in Japan.

The drug is targeted at patients with intractable epilepsy who have difficulty responding to existing drugs. If it gains approval, it could become the first therapeutic drug derived from cannabis to be marketed in Japan.

There are estimated to be 10,000-20,000 patients who could benefit from the medicine, which is marketed as Epidiolex overseas.

The Cannabis Control Law prohibits the possession of cannabis and the use of cannabis in medicine. The Health, Labor and Welfare Ministry plans to revise the law so patients can promptly receive treatment with the drug once its use is approved.

The medicine was approved in the United States in 2018 and in Europe in 2019.

The health ministry gave the green light for clinical tests in March 2019, amid calls from families of patients with intractable epilepsy and others for the government to approve the medicine.

The upcoming trial will involve patients aged 1-65 with any of three kinds of intractable epilepsy, including Dravet Syndrome.

Over a period of four months, 84 patients will take the oral medication daily at about 20 medical institutions, which will record the frequency of epileptic seizures and the presence of side effects. Patients will continue to take the medicine for another 12 months to confirm its safety. In an overseas study, the drug reduced seizures by nearly 40% in recipients.

Measures needed to prevent abuse

By Ryuya Hara / Yomiuri Shimbun Staff Writer

The move to launch clinical trials of a CBD drug in Japan is in line with a global trend of using cannabis-derived products for medical purposes.

CBD is said to be effective in reducing the frequency of epileptic seizures without inducing the highs associated with cannabis use. It is also being used in drugs to treat other intractable diseases in some countries.

Explaining the significance of the planned clinical trials in Japan, Ichiro Takumi, professor of neurosurgery at St. Marianna University School of Medicine, said, “It will help expand treatment options for patients with intractable epilepsy.”

However, there is concern that lifting the ban on the use of cannabis-derived products for medical purposes could spread a misconception that cannabis is safe.

Cannabis is considered to be a “gateway drug” that can lead to more dangerous drugs such as illegal stimulants.

The number of people caught in connection to cannabis is on the rise. Of the 5,783 recorded offenses last year, 70% involved people under 30.

Although there are cases of regulated drugs being used in pharmaceuticals, such as the painkiller morphine, strict controls are imposed.

The government must enhance measures to prevent cannabis abuse, such as raising awareness of the harmful effects of the drug.