Earlier this week, positive results were released from a clinical study testing a combination of tetrahydrocannabinol (THC) and cannabidiol (CBD) as a treatment in recurrent glioblastoma (GBM) patients in the UK.
The drug being tested, called Sativex, has been developed by GW Pharmaceuticals and is currently approved for use in multiple sclerosis patients for muscle spasms in a number of worldwide countries.
GBM is the most common high grade brain tumour in adults, for which existing treatments like chemotherapy and radiotherapy give little benefit.
This study involving 21 patients showed that those treated with a combination of THC and CBD alongside chemotherapy drug temozolomide (TMZ) had an 83% one year survival rate compared with 53% for those who didn't receive the drug. The median survival for the treated group was greater than 550 days compared with 369 days in the group who didn't receive the drug.
“The findings from this well-designed controlled study suggest that the addition of a combination of THC and CBD to patients on dose-intensive temozolomide produced relevant improvements in survival compared with placebo and this is a good signal of potential efficacy," said Professor Susan Short, PhD, Professor of Clinical Oncology and Neuro-Oncology at Leeds Institute of Cancer and Pathology at St James's University Hospital and principal investigator of the study.
“Moreover, the cannabinoid medicine was generally well tolerated. These promising results are of particular interest as the pharmacology of the THC:CBD product appears to be distinct from existing oncology medications and may offer a unique and possibly synergistic option for future glioma treatment".
In previous research, cannabinoids have been shown to work by enhancing the process of self-destruction of cells in the body (known as autophagy) through a number of different ways. One of the pathways that they act on is the AKT/mTOR pathway, which is overactive in a number of different cancers.
So what do these findings mean for GBM patients?
As a Charity, we are very excited by the results that have come out of this trial as it paves promise for new treatments of highly aggressive brain tumours. We believe that clinical trials, such as this, are vital to establish whether a new approach is better than the old one - if it isn't, there is little point in persisting with it.
Read more about how you could take part in a clinical trial.
This clinical trial was designed to test the safety and effectiveness of using Sativex in a small group of GBM patients. The next stage will be to look at whether Sativex works better than standard treatment or whether it produces fewer side-effects. Although a large amount of progress has been made, it could be up to another five years before this drug is licensed for use in brain tumour patients.
“Medicines and products derived from cannabis have caused some controversy in the past because cannabis and cannabis oil both of which contain the psychoactive component THC are classified as a class B drug in the UK meaning that it is illegal to possess or supply them. Despite it being illegal we know that some people in our community use cannabis and cannabis oil. It is of paramount importance that robust clinical trials like this one take place to demonstrate efficacy and legitimise cannabis based treatments," says Beccy Shortt, Senior Policy and Public Affairs Manager.
“Many of our community also access CBD in the form of CBD oil which is currently legal but which the Medicines and Healthcare Regulatory Authority are proposing should be regulated as a medicine. If this happens, we do not know currently whether people will continue to be able to legally access it. We will continue to campaign for more innovation in treatments including exploration of the therapeutic value of medicines derived from cannabis and we will campaign to ensure that our community can continue to legally access CBD oil."
You can read more about the legal situation around cannabis and CBD oil in our position statements. Additionally, if you have any questions about cannabis or CBD oil, please contact our Support & Info Team.