The concept of cannabis curing cancer may be hard to imagine, but evidence from cell cultures and animal studies has already proven the possibility. Now researchers say they’re ready to move to the clinical stage.
Dr. Sean McAllister, of the California Pacific Medical Center (CPMC), has spent nearly a decade studying the effects of cannabidiol – a chemical found in marijuana – on aggressive types of breast and brain cancer.
His research has already shown that cannabidiol (CBD) can reduce the spread of cancer to other parts of the body. Although, so far, he’s only been able to study animal and cell culture models. Now he says his team is ready to prove it in humans.
“We are trying to initiate clinical trials in the US. We have designed the trials for breast and brain cancer but are still trying to raise the money for the trials.”
Since last year, Dr. McAllister has been going through the difficult and lengthy process of initiating clinical trials. With study designs complete, funding seems to be the only obstacle that remains.
If all goes as planned, he hopes to see CBD being trialed in cancer patients “a year from now.”
But it’s not only Dr. McAllister that sees promise in cannabis for cancer. A drug company called GW Pharmaceuticals is also trying to study a cannabis-based drug, Sativex, as an add-on treatment for glioblastoma – the most common and deadly form of brain cancer.
The company has already begun recruiting patients for the first phase of clinical trials in Europe. Researchers will first have to prove its safety in a small group of glioblastoma patients before they can start evaluating Sativex’s effectiveness at fighting cancer.
According to Dr. McAllister, preclinical research suggests that cannabinoids, while effective alone, may have a greater effect against cancer when combined with current treatments.
“Based on the data, it would be expected that cannabinoids would need to be combined with a first-line agent in order to see the most efficacy in a clinical setting.”
Dr. McAllister’s breakthrough came in 2007, when his team at CPMC showed that cannabidiol could reduce tumor aggressiveness in breast cancer by “turning off” a protein responsible for the spread of cancer, or metastasis, called Id-1.
Four years later, they were able to confirm the effect in mice, showing that CBD treatment could reduce the number and size of secondary tumors that formed.
Another of his studies, this time in glioblastoma cell cultures, found that CBD and THC could work together to achieve an even greater effect, concluding that “the addition of cannabidiol to Delta(9)-THC may improve the overall effectiveness of Delta(9)-THC in the treatment of glioblastoma in cancer patients.”
“You have to build a strong case for clinicians to agree to run clinical trials. We are there now.”While THC also demonstrates anti-cancer potential, Dr. McAllister explains that one of the reasons he chose to study CBD is the lack of psychoactivity – or a high – which could be a concern when conducting studies in humans.
Another obstacle has been gathering enough evidence on the treatment. Despite an abundance of anecdotal reports of cannabis successfully curing cancer, it’s taken Dr. McAllister years of effort to “build a strong case” for clinical trials.
But now he says the time has come.
“It takes a significant amount of time to run preclinical experiments,” Dr. McAllister explains. “You have to build a strong case for clinicians to agree to run clinical trials. We are there now.”