Ana Watson gives her son Preston Raynor a dose of cannabidiol oil made by a Colorado medical marijuana non-profit group. The two are in the recovery room at Children's Hospital Colorado in Aurora on Sept. 15, 2014, after Preston had surgery for a feeding tube. Preston has a type of epilepsy known as Dravet syndrome, and his family relocated to Colorado from North Carolina to try the treatment. (Joe Amon, The Denver Post)

Two studies on CBD use for epilepsy show encouraging results

Both small-sample studies used GW Pharmaceutical's investigational medicine Epidiolex, a liquid formulation of cannabidiol (CBD); scientists cautioned further research is needed before the results can be confirmed

For a number of years now, families of children with epilepsy have been relocating to Colorado from around the world to try to obtain a special marijuana extract known as “Charlotte’s Web” that they had heard had an almost magical ability to reduce seizures. In late 2013 and early 2014, as the political movement to legalize medical marijuana was heating up, many of these parents traveled to state capitals around the country to plead for help in getting access to similar treatments. More than a few legislatures, regardless of their stance on marijuana, were so moved by the stories that they acquiesced.

The reaction from the scientific community was more cautious.

Some researchers dismissed the reports of recoveries — shared widely on social media — as wishful thinking. Others launched clinical trials to try to figure out what was going on.

Early results, unveiled at the American Epilepsy Society’s annual meeting in Philadelphia this week, are encouraging.

The first study, led by Orrin Devinsky, director of the comprehensive epilepsy center at NYU Langone Medical Center, involved giving a drop of liquid cannabidiol (CBD), a key component of marijuana, to 261 patients with severe epilepsy for three months. The participants, most of whom were children with an average age of 11 and were at 16 different sites around the country, continued to take their regular anti-seizure medications as well.

By the end of that time period, their seizures were reduced by 45 percent on average. But the treatment wasn’t without risks. Some 5 percent of the patients had side effects, such as changes in their liver enzymes or diarrhea. Twelve percent stopped taking the medication in the middle of the study because it didn’t appear to help.

Devinsky called the data “promising” and said that they provide “hope to the children and their families who have been living with debilitating seizures.”

The second study, conducted at the University of California Benioff Children’s Hospital, involved fewer participants — only 25, and all children — but involved giving the drug for a longer time period — one year. The results were more mixed than in the previous study. Ten of those children experienced at least a 50 percent reduction in their seizures. But 12 of the children stopped taking the medication because it didn’t work, and one because his seizures became more frequent.

Both studies used GW Pharmaceutical’s investigational medicine Epidiolex, a liquid formulation of cannabidiol.

The scientists cautioned that their results are from a small sample, studies that did not have control groups, and that further research is needed before the results can be confirmed. Additional data is expected to be released in 2016.