Date: 05 Aug 2021
News Source: www.theguardian.com
First such study in the world aims to find out if Sativex combined with chemotherapy can help treat glioblastoma
Cancer charities and the NHS are preparing to investigate whether a cannabis-based mouth spray can treat brain tumors and help patients to live longer.
Doctors will give patients across the UK with a recurrent brain tumor called a glioblastoma the drug, which is known as Sativex, alongside a chemotherapy medication – temozolomide – in a clinical trial in an attempt to kill off cancerous cells.
It will be the first such study in the world.
Glioblastoma is an aggressive and hard-to-treat form of brain tumor that almost always comes back, despite doctors using surgery, radiotherapy, and chemotherapy to tackle it. Those diagnosed only live for 12 to 18 months while those with recurrent glioblastoma survive for just 10 months.
About 2,200 people in England are diagnosed every year with the condition, making it the commonest form of brain cancer.
Sativex is already given to patients with multiple sclerosis whose condition has not improved despite treatment, in order to reduce their spasticity. It is one of three cannabis-based medicines currently in use in the NHS.
“We think that Sativex may kill glioblastoma tumor cells and that it may be particularly effective when given with temozolomide chemotherapy, so it may enhance the effects of chemotherapy treatment in stopping these tumors growing, allowing patients to live longer, said Susan Short, a professor of clinical oncology and neuro-oncology at Leeds University, who is the principal investigator of the study. “That is what we want to test in the study,” she said.
The Brain tumor Charity, which is funding the trial, will recruit 232 patients early next year from at least 15 hospitals, including specialist cancer centres, across the UK. Two-thirds will receive Sativex and temozolomide while the other third will be given the chemotherapy drug and a placebo.
Sativex contains equal amounts of two cannabinoids: the psychoactive substance Delta-9-tetrahydrocannabinol (THC), which gives users a “high”, and cannabidiol (CBD), which can help reduce pain, inflammation, and anxiety without inducing any psychoactive effects.
“We hope this trial could pave the way for a long-awaited new lifeline that could help offer glioblastoma patients precious extra months to live and make memories with their loved ones,” said Dr David Jenkinson, the Brain tumor Charity’s interim chief executive.
“We know there is significant interest in our community about the potential activity of cannabinoids in treating glioblastomas, and we’re really excited that this world-first trial here in the UK could help to accelerate these answers.”
The trial follows an earlier study – a phase one trial – that looked purely at the safety of giving Sativex and temozolomide together, which involved 27 patients. The new three-year trial, called the Aristocrat study, will look at both the safety of that regime and what impact it has on the patient’s outcome, including how long they survive for.
“The recent early-stage findings were really promising and we now look forward to understanding whether adding Sativex to chemotherapy could offer life extension and improved quality of life, which would be a major step forward in our ability to treat this devastating disease,” added Jenkinson.
Short said that the initial study suggested that the drug could give some people some extra life. More participants who had Sativex were still alive a year later than those who had a placebo.
“It showed that this combination was safe, although some patients had problems with side-effects including sickness, tiredness and dizziness.
“The study was not designed to test whether Sativex was better in terms of survival. But it did suggest that some patients who had Sativex did better than expected and better than those who just had chemotherapy,” she said.
The Brain tumor Charity plans to push ahead with the trial but stressed that doing so depended on the results of an appeal to help cover the £450,000 costs involved. It has suspended its usual programme of research grants after losing 25% of its income during the COVID-19 pandemic.
The new study is being coordinated by Cancer Research UK’s clinical trials unit at Birmingham university. “It is vital that trials like this, investigating the role cannabis or the chemicals in it can play to treat cancer, are carried out,” said Prof Pam Kearns, the unit’s director.