Cannabis: Treatment for Brain Cancer?
First human trials of cannabis as a treatment for aggressive brain cancer are underway.
In November 2013, GW Pharmaceuticals based in the UK started its clinical trials of Sativex to determine its usefulness against aggressive brain cancer. (Sativex is approved and used successfully in more than 20 countries for the treatment of multiple sclerosis symptoms.)
The company created Sativex as an oral spray from some of the ingredients derived from the cannabis plant. Cannabis has two main compounds, CBD and THC, which are both in Sativex in equal ratios.
These compounds are known as cannabinoids and have proven in pre-clinical studies to have anti-cancer elements. Unofficially, cannabinoids seem to be an effective tool against a variety of cancers.
This is the first company to begin clinical research using a cannabis medicine for cancer therapy treatment. Preclinical studies were funded and conducted by GW, but this is the first of its studies to use human patients to test cannabis-based medicine for potential treatment to inhibit the growth of tumors.
The Sativex Clinical Trials
The preclinical studies show cannabinoids may enhance the anti-cancer effects of temozolomide, a standard chemotherapy agent. As a result, GW Pharmaceuticals will use Sativex as an add-on to temolozomide.
The clinical trials will be comprised of 20 patients with recurrent glioblastoma multiforme (GBM). This rare and aggressive brain cancer accounts for roughly half of the US diagnoses of all brain cancers annually.
The first important hurdle for the study is to establish the safety of the combined temozolomide/Sativex regimen. Once the study proves the combination is safe, more research can be conducted on its actual effectiveness.
Other Cancer Trials Using Cannabinoids
Because cannabis is classified as a Schedule 1 drug, research into the effects of cannabis as an actual medicine has been greatly stymied in the US.
However, in other countries, researchers have conducted and published reviews of cases in which some cannabis extract successfully treating other cancers such as leukemia and breast cancer.
In October 2013, Dr. Wai Liu, a UK researcher, published his findings that proved cannabinoids can kill leukemia cells. Liu told U.S. News the cannabinoids displayed “potent anti-cancer activity” and can “target and switch off” cancer pathways.
In the study, he tested six cannabinoids—combined and independently—on leukemia cells, which "resulted in dramatic reductions in cell viability" and "caused a simultaneous arrest at all phases of the cell cycle." Liu expects clinical trials to begin soon for new medications.
To date, the NCI has yet to fund research to study cannabinoids’ effects on leukemia. While it may seem only minimal efforts have been made, the National Cancer Institute has funded “some” research into using cannabis to treat cancer, most notably a preclinical study in 2012 looking at the use of cannabinoids to slow breast cancer.
Researcher Dr. Sean McAllister of California Pacific Medical Center expects to begin the first human clinical trial of CBD for breast cancer treatment in 2014.
What’s Next?
GW Pharmaceuticals has introduced other cannabinoid drugs, for example, Epidiolex, which is being studied for its use in epilepsy patients.
Unlike Sativex, which includes CBD and THC, Epidiolex is nearly pure CBD. Clinical trials have recently begun in the US and the UK as a treatment for epilepsy in children. The US study has the distinction of being the first ever FDA-approved cannabis-based drug study for children with epilepsy.
In December 2013, GW Pharmaceuticals made public it had received a Notice of Allowance from the U.S. Patent Office for a 2009 patent application involving the use of cannabis’ THC and CBD for treating gliomas brain cancer.
While the patent isn’t a done deal, the Notice of Allowance typically precedes payment of fees associated with final approval.
Amazingly, the patent was filed in 2009, yet GW’s first clinical trial investigating these cancer treatments just began in November 2013.
