Sam Mountney, Senior Policy & Campaigns Officer at Epilepsy Action, shares his expertise on cannabis-based medicines as a treatment for epilepsy in the UK
Cannabis has continued to divide opinion since the government rescheduled cannabis-based medicines in November 2018, legally permitting them to be prescribed. Prior to this cannabis and cannabis derivatives were largely classified as schedule 1 controlled substances, with an associated narrative centred on prohibition, addiction and potential adverse health effects.
This law change has led to an increasingly informed and nuanced discussion focussed on the scientific facts and clinical evidence around the potential benefits of cannabis-based medicines to treat a number of long-term health conditions, including epilepsy.
For context, cannabis-based medicines is a blanket term for products containing cannabis or cannabis derivatives that are produced and regulated as medicinal products for humans.1 As with most medicines, it is two active compounds present in the cannabis plant, specifically cannabidiol (CBD) and tetrahydrocannabinol (THC) that are of clinical significance and the current focus of debate.
CBD, a non-psychoactive cannabinoid, seems to be following in the footsteps of turmeric and aloe vera in its portrayal by some as the next holistic super supplement. In comparison THC, a psychoactive cannabinoid associated with the sensation of getting ‘high’ in the recreational context, continues to be viewed with caution.
There are a myriad of CBD products available as over the counter ‘supplements’ sold in health food shops across the country. These products are not of a pharmaceutical standard and by law cannot claim any medical benefits. They often contain very low quantities of CBD and have no notable clinical effects.
However, there is good quality clinical evidence for the safety and efficiency of CBD-containing medicine Epidyolex as an add-on treatment for two severe and life-limiting intractable epilepsy syndromes, Lennox-Gastaut and Dravet syndromes. This evidence is in the form of Randomised Controlled Trials (RCTs), the ‘gold standard’ of clinical evidence. The existence of positive RCT evidence has resulted in Epidyolex receiving marketing authorisation for these indications in the U.S. and, since its approval in September, Europe, including the UK.
The lack of such evidence for other cannabis-based medicines, particularly those containing both THC and CBD, is proving to be a critical stumbling block to access for people with epilepsy.
The powerful and compelling stories of Billy Caldwell and Alfie Dingley, two young boys with severe and treatment-resistant epilepsies, became front-page news in the UK last year and played a critical role in the change in the law. Both had been treated with cannabis-based medicines containing THC and CBD abroad and showed notable clinical improvements in seizure control and quality of life. Tireless campaigning by their mothers led to both children being prescribed medicine containing both THC and CBD on the NHS. They remain the only two NHS prescriptions of this type that we are aware of.
It is a bitter irony for many people affected by severe and treatment-resistant epilepsies that the very cannabis-based medicines that led to the change in the law are as inaccessible now as they were before. Despite THC’s incarnation as a chemical bogeyman, many families of children affected by severe epilepsies are convinced that medicines with a 1:20 or 1:1 ratio of THC: CBD are the most effective. This is not without basis. Other G7 countries, most notably Canada and the United States, and European Union Member States such as the Netherlands, allow varying degrees of access to treatments containing both THC and CBD for epilepsy. In the Canadian example, the lack of RCT evidence is weighed against data from observational trials, pre-clinical studies and available evidence on the endocannabinoid system and epilepsy.2
Initial interim clinical guidance for both paediatric and adult epilepsies recommend against prescribing products containing THC and CBD in almost all circumstances. Recent draft guidance from the National Institute for Health and Care Excellence (NICE), which will ultimately supersede the interim guidance, indicates this is unlikely to change. A separate NICE technical appraisal process is ongoing in respect of Epidyolex to treat Lennox-Gastaut and Dravet syndrome and a decision is expected later in 2019.
Epilepsy Action is in complete agreement with clinicians, regulators, and the government about the need for more high-quality research. A recent NHS report3 indicates the strongest commitment so far to move this research forward at pace. Commitments of political will and, crucially, funds for vital research are welcome, but they must be followed through.
Almost a year after the change in the law, patients remain unable to access cannabis-based medicines for epilepsy in all but a minority of cases and the debate continues. In one respect, the need for high-quality clinical evidence is a routine and necessary debate around access to medicines. In another, this debate is unique in trying to unpick decades of prohibition and instigating a battle between avid campaigners calling on compelling anecdotal evidence and international research to push for immediate access, and a UK regulatory system that will seemingly only accept the elusive gold standard RCT evidence.
Epilepsy Action is committed to ensuring people with epilepsy can access the best drugs at the right time. Though by no means a magic bullet, the hopes of many affected by severe and treatment-resistant epilepsies are firmly hung on cannabis-based medicines. Hope is often in short supply for these people and there is a clear need for a short-term solution to allow compassionate access for those who could benefit. The time for waiting is over, the time for action is now.
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