Groundbreaking clinical trials in the UK are poised to explore the effects of cannabis-based oral treatment on patients with recurrent brain tumours.
The drug, Sativex, which contains a mixture of THC and CBD, is available as a mouth spray and was previously approved by the UK’s National Health Service in 2019 as a treatment for muscle spasms linked to multiple sclerosis.
The NHS now seeks to trial the spray alongside chemotherapy medication temozolomide in a bid to kill cancerous cells in glioblastoma, an aggressive type of cancer that occurs in the brain or the spinal cord. With an incidence rate of around 1 in 10,000, glioblastoma is among the rarest forms of cancer. Still, representing 16% of all primary brain tumours, it’s the most common brain malignancy and is almost always lethal.
The Brain Tumour Charity has launched an appeal for funding, hoping to raise £450,000 to finance the trial scheme, which would run for three years. If successful, the drug would represent the first breakthrough in the treatment of glioblastoma in over a decade.
How Sativex is Used
Sativex contains two chemical extracts found in cannabis: delta-9 THC and cannabidiol, and at present, it is delivered as an oromucosal spray. The number of sprays is increased gradually until the optimum dose is reached, over the course of days up to two weeks, depending on the recipient. In Multiple Sclerosis-related symptoms, Sativex gives relief from muscle stiffness with few side effects(i).
The trial represents a landmark moment in cancer treatment via cannabis extracts, as, at present, this remains unapproved in the UK. Success could mean a green light from the medical community, and that could open the floodgates for a host of new cannabis-based treatments across a broad spectrum of conditions, as well as hope for cancer patients. At present, the only other cannabis-based medicines approved for use in the UK is Epidyolex, an oral solution which clinical trials found could reduce the number of seizures in children with epilepsy by up to 40%, and Nabilone, a synthetic THC.
Legal Classification of Sativex in the UK
Due to its cannabis-based content, Sativex is classed as a controlled drug and classified by its potential for harm and implications for possession and inappropriate supply under the UK’s Misuse of Drugs Act 1971 as a Class B drug, alongside amphetamines and barbiturates. It is placed in Schedule 4 of the Misuse of Drug Regulations 2001, which allows legal prescription in the UK without restriction on supply, storage, recording, or destruction(ii)
Since being licensed, several studies have been published analysing data on Sativex, one of which showed that approximately 8 out of 10 people benefited from treatment(iii).
Optimism Among the Medical Community
There is optimism among the medical community that Sativex could produce positive results, with the professor of clinical oncology and neuro-oncology at University of Leeds, Susan Short, recently telling the BBC: “Having recently shown that a specific cannabinoids combination given by oral spray could be safely added to temozolomide chemotherapy, we’re really excited to build on these findings to assess whether this drug could help glioblastoma patients live longer.”(iv)
Dr. Cristina Sanchez, a professor of biochemistry and molecular biology at Universidad Complutense in Madrid, has spent over a decade researching the anti-tumour effects of cannabinoids. Dr. Sanchez’s work continues to blaze a trail for cannabis use in medicine, and in an interview with Cannabis.es in June 2021, she stated: “We have worked on breast cancer for a long time. We have observed that there are similarities between this cancer and glioblastoma: specifically, the fact that cannabinoids induce the death of the tumour cells and inhibit the progress of tumours. It is something found in many different tumours, like the brain, breast, pancreas tumours… in other words, all the classifications that we have been able to analyse, not only us but also other groups of investigation around the world.
We know that the active mechanisms are different, but it’s the same response to anti-tumour cannabinoids”.(v)
This new trial is welcomed by the cannabis community, where anecdotal evidence has been gathered for decades detailing the medical benefits of both THC and CBD on various ailments, including cancer, glaucoma, MS, and epilepsy. But with the professional medical community largely reluctant to pursue the use of cannabis as a treatment, and in most cases, bound by legislation – people have turned to CBD products, or the now-famous Rick Simpson Oil, as a way to self-medicate. In the case of terminal diagnoses, cancer patients, in particular, have taken their health into their own hands and tried many unconventional treatments, cannabis being one of these. This latest trial indicates that science is finally catching up with what medical cannabis users have been saying for years, and successful trials involving Sativex on glioblastoma patients may herald a new dawn for cannabis as a powerful option in the treatment of cancer.[i, iii]https://mstrust.org.uk/a-z/sativex-nabiximols [ii]https://release.org.uk/law/classes [iv]https://theguardian.com/society/2021/aug/03/trial-to-test-if-cannabis-based-mouth-spray-can-treat-brain-tumours [v]https://www.cannabis.es/pw/en/2021/06/10/cristina-sanchez-spain-leads-medical-cannabis-research-but-stands-last-in-implementation