Two national NHS clinical trials will investigate the safety and effectiveness of cannabidiol (CBD) and tetrahydrocannabinol (THC) in adults and children with treatment-resistant epilepsy.
Prof Finbar O’Callaghan and Prof Helen Cross from University College London (UCL) and Great Ormond Street Hospitals (GOSH) will co-lead the trials, which are due to start in 2025.
The trials will randomly assign CBD, CBD with a small amount of THC or placebo to a total of 500 adults and children with medicine-resistant (refractory) early-onset and genetic generalised epilepsies for 24 weeks. People will be recruited into the trial from NHS sites around the UK. The trial will use formulations by the company Ananda Developments, known as MRX2 (CBD) and MRX2T (CBD+THC).
The researchers want to investigate whether these medicines are safe and effective in reducing number and severity of seizures, and how they affect learning, sleep, behaviour, quality of life, stress and anxiety.
Ananda Developments said: “These will be the world’s first double blind randomised controlled trials to investigate the use of CBD and THC together for epilepsy, and the first to evaluate the medicines in children and adults who have a broad range of difficult-to-treat epilepsies.”
If successful, the results of the trials may support applications to the Medicines and Healthcare Products Regulatory Agency (MHRA) and other regulatory bodies for approval for use in refractory epilepsy.
At the moment, the CBD medicine Epidyolex is licensed and recommended for use on the NHS for people with Dravet syndrome and Lennox-Gastaut .
Currently, the National Institute for Health and Care Excellence (NICE) has not recommended this medicine for severe and treatment-resistant epilepsies. The institute says more high-quality evidence is needed on safety and effectiveness of CBD and CBD in combination with THC for severe treatment-resistant epilepsy.
Much-needed research
Rebekah Smith, deputy chief executive at Epilepsy Action, said: “It’s encouraging to see these long-anticipated trials for medicinal cannabis finally taking place. The NHS has had a cannabidiol product available since 2018, but there have been very few prescriptions, and it has only been approved for two rare forms of epilepsy.
“The need for more research on the effectiveness and safety of both the CBD and THC elements of cannabis is much needed, and announcing this research is a source of hope for many families.
“We are eager to understand how these clinical trials could advance the way we treat epilepsy, and while we recognise that this will take time, we will continue to inform and educate people about their options and support them in ways to access this and other forms of medication.”
Matt Hughes, co-founder and director of Medcan Family Foundation, said: “We are pleased to hear that the long-anticipated trials proposed by GOSH and UCL in 2019 will commence next year.
“Research is a much-needed step in expanding access to CBD medicines for the treatment of drug-resistant epilepsy. The trials bring renewed hope for children and families affected by uncontrolled seizures.
“A trial including THC is also crucial for addressing the questions posed by NICE.
“However, it’s important to recognise that these trials do not include second generation, advanced cannabinoid medicines; the variety that is used by most families seeing significant and sustained improvements in seizure control and which have been shown through real-world data and observational trials to be the most effective.
“For those for whom CBD and THC alone are not effective, and for those already privately prescribed advanced cannabinoid medicines, we continue to urge government support in creating a pathway for the licensing of these more advanced medications.”
There’s more information on medical cannabis in the UK on the Epilepsy Action website.
