The world’s first human trial to test a cannabis-based drug for brain cancer therapy has now begun in the UK.
Cannabis is slowly gaining traction among researchers for its medicinal properties. Previous studies have proven the psychoactive drug to be effective for migraines, childhood epilepsy, and several other conditions. Now, researchers in the UK have begun testing cannabis for the treatment of an aggressive brain cancer, called glioblastoma.
Glioblastoma is the most common and aggressive form of brain cancer in adults. With a less than 6% 5-year survival rate, the tumour poses significant challenges for doctors. Treatment generally involves a combination of surgery, radiation, and chemotherapy. However, despite all this, almost all patients face a recurrence of the tumour 6-9 months after treatment. Moreover, the survival rate worsens after recurrence. Therefore, there is an urgent need for more effective therapeutic options.
Over the past few years, researchers have tested cannabinoids for treating brain tumours. Several studies have found a significant impact on tumour growth and patient survival. Cannabinoids, tetrahydrocannabinol (THC) and cannabidiol (CBD) have both shown success in inhibiting tumour growth in animal models. Moreover, glioblastoma tumours contain cannabinoid receptors on their cell surface. Therefore, researchers predict that the drug in combination with chemotherapy can likely slow tumour growth in patients.
The ARISTOCRAT Trial
Led by Professor Susan Short from the University of Leeds, the new phase II trial (ARISTOCRAT) will recruit over 200 participants for their study. The trial aims to treat glioblastomas with a combination of cannabis and chemotherapy. The researchers will administer a cannabis-based oral spray called Sativex to patients. It contains a combination of THC and CBD in equal concentrations. The oral spray is currently used for treating muscle spasms in patients with multiple sclerosis.
As per the study design, one-third of the patients will receive temozolomide chemotherapy and a placebo. While the rest of the patients will receive Sativex and the chemotherapeutic agent. The patients will administer up to 12 sprays per day. Moreover, researchers will regularly monitor the patients using blood tests, MRI scans, and questionnaires.
Earlier this year, phase I trials of the spray had shown the drug to be safe for use in glioblastoma patients. However, it could not assess the efficacy of the drugs. The phase II trial will likely offer information on the drug’s therapeutic potential for brain cancer treatment.
Twelves, C., Sabel, M., Checketts, D. et al. A phase 1b randomised, placebo-controlled trial of nabiximols cannabinoid oromucosal spray with temozolomide in patients with recurrent glioblastoma. Br J Cancer 124, 1379–1387 (2021). https://doi.org/10.1038/s41416-021-01259-3