The stratospheric rise of medical marijuana as a possible recognized treatment for epilepsy, now underway, is an example of what can be achieved through the sharing of personal stories on the Internet and social media, according to a leading expert in the field.
Daniel Friedman, MD, New York University (NYU) Langone School of Medicine, is a coauthor a review article, “Cannabinoids in the Treatment of Epilepsy,”published in the September 10 issue of The New England Journal of Medicine.
“It is a very interesting mix of science, politics, and social phenomena which has moved medical marijuana to the forefront of treatment for severe drug-resistant epilepsy,” he commented to Medscape Medical News. “Two years ago the epilepsy community wasn’t really seriously considering this as an option. But it has now really taken off.”
Dr Friedman noted that the idea that marijuana may be useful for epilepsy has been around for centuries. “It was used medicinally in ancient China and by Victorian neurologists for seizures, but it has never been properly scientifically studied. That is now happening.
“This has come about because individuals have shared anecdotal experiences about its effectiveness in children with severe intractable epilepsy on the Internet and these have spread across the globe,” he added. “Once it became ‘out there,’ families have been clamoring for access to the product and we have had to pay attention. That is why medical marijuana is being legalized and studies are finally being done.”
But in the review, Dr Friedman and his coauthor, Orrin Devinsky, MD, also from NYU Langone School of Medicine, caution that it is of the utmost importance that the double-blind, randomized studies now underway are completed.
“The use of medical cannabis for the treatment of epilepsy could go the way of vitamin and nutritional supplements, for which the science never caught up to the hype and was drowned out by unverified claims, sensational testimonials, and clever marketing,” they write.
Two cannabinoid pharmaceutical products are under study in randomized trials. These are Epidiolex (GW Pharma), a purified cannabis extract containing 99% cannabidiol (the constituent believed to have the antiseizure effect) and less than 0.10% tetrahydrocannabinol (the psychoactive component) and a synthetic cannabinoid from Insys Pharmaceuticals.
Dr Friedman and Dr Devinsky are both involved in a double-blind, phase 2/3 trial of Epidiolex in children with Dravet syndrome — a treatment-resistant form of childhood epilepsy — from which initial results are expected within the next year.
“Watch This Space”
“It’s very much ‘watch this space’ at the moment,” Dr Friedman commented to Medscape Medical News. “There is emerging evidence on efficacy. The preclinical evidence is reasonably strong for cannabidiol, similar to that for a new pharmaceutical for epilepsy. The clinical data are still early. So far the studies have been small and methodologically flawed, but results are encouraging.”
He highlighted the additional difficulties in making randomized trials happen with cannabinoid products.
“There are regulatory issues because these are all schedule I compounds they have many restrictions, so clinical trials have too many additional layers of regulatory bureaucracy,” he said. “Then there is the issue of public perception: there is a disconnect between what we know about efficacy from scientific literature and what the public perceive the evidence to be. Many states have legalized medical marijuana for several conditions, including epilepsy, so there is the perception that it has been proven to work, but this is not the case. I worry about the high expectations — this could confound clinical trial results by leading to a very high placebo response.”
He said his advice to patients has evolved, and he now recommends that if they haven’t exhausted proven effective therapies, they pursue agents that are known to work and have a well-understood benefit/risk profile. “But for patients who have exhausted such therapeutic options and can access cannabinoids, I would advise them to have a discussion with their physician about whether such an approach would be appropriate for them.”
He noted that most patients can now access some form of cannabinoid product, with medical marijuana now available in 23 US states and patients everywhere able to access hemp products via the Internet.
“If randomized clinical trials show that specific cannabinoids are unsafe or ineffective, those preparations should not be available,” they add. “If studies show that specific cannabinoids are safe and effective, those preparations should be approved and made readily available.”
Dr Friedman has received fees for serving on an advisory board for Marinus Pharmaceuticals and consulting fees from Eisai, Marinus Pharmaceuticals, SK Biopharmaceuticals, Upsher-Smith Laboratories, and Pfizer, all of which were paid to the Epilepsy Study Consortium.
N Engl J Med. 2015;373:1048-1058