The UK National Health Service (NHS) and the Brain Tumour Charity are investigating whether cannabis-based mouth spray Sativex can help treat brain tumours and improve the lifespan and quality of life of those living with glioblastoma.

The first-of-its-kind trial will see 232 patients with glioblastoma recruited early next year from at least 15 hospitals across the UK. Two-thirds will be given Sativex, alongside chemotherapy medication temozolomide, in an attempt to kill off cancerous cells. The other group will be given temozolomide and a placebo.

Sativex, one of three cannabis-based medicines currently available under the NHS, is used to reduce spasticity in multiple sclerosis sufferers.

Leeds University professor of clinical oncology and neuro-oncology and principal investigator Susan Short told The Guardian the new study will test the efficacy of the drug for glioblastoma.

Professor Susan Short: Sativex may kill glioblastoma tumour cells

She added: “We think Sativex may kill glioblastoma tumour cells and be particularly effective when given with temozolomide chemotherapy, so it may enhance the effects of chemotherapy treatment in stopping these tumours growing, allowing patients to live longer.”

Sativex contains an equal amount of cannabis extracts Delta 9 THC and CBD.

Around 2,200 people in England are diagnosed every year with glioblastoma, an aggressive and hard-to-treat brain tumour with a high recurrence rate. The lifespan for those diagnosed is only 12-18 months, and 10 months when the cancer is recurring.

The Brain Tumour Charity is funding the study, with interim chief executive Dr David Jenkinson hoping the trial will pave the way for new treatments that could help offer glioblastoma patients precious extra months to live.

He added: “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 findings from stage one of the study, which tested the safety of giving Sativex and temozolomide together and involved 27 patients.

The new trial will run for three years and investigate both the safety of that regime and what impact it has on patient outcomes, including how long they live.

The findings from stage one indicate that Sativex could increase life expectancy for some patients, as more participants who were given the drug were still alive a year later than those who had a placebo.

Short said: “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.

“It showed that this combination was safe, although some patients had problems with side effects including sickness, tiredness and dizziness.”

Jenkinson added: “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.”