The results of that trial were published in 2006. Now, Dr Velasco is preparing for another clinical trial, expected to begin recruiting this year, of the cancer-fighting effects of cannabinoids. One issue limiting the number of clinical trials, he said, is that major pharmaceutical companies are reluctant to gamble on expensive research of a plant product that just about anyone can produce on their own.
“THC and CBD, the 2 natural cannabinoids compounds that show the most potent anticancer activity in animal models, cannot be patented,” he said. “Most companies would not invest in clinical studies unless they have their own proprietary compound(s) that may yield significant profits afterwards.”
Ofra Benny, PhD, a researcher at The Hebrew University of Jerusalem’s Multidisciplinary Center on Cannabinoid Research in Israel, is taking a different approach.
Dr Benny is working to identify specific cannabinoid compounds with anticancer effects, which can be developed into drugs whose production is controllable.
“Unlike most researchers, we’re looking at specific compounds because we think it will be easier to create drugs with them, rather than use the oil extract or a mixture of hundreds of different compounds,” she said by telephone from Israel.
That focus, she said, could allay the concerns of drug makers.
“Coming from pharmaceutical research, we know that it will be easier to handle with small molecules — very defined molecules,” she continued. “We’re trying to take one of them, the most potent one that we eventually find, and we will try to translate that to the clinic. And hopefully this will be a faster track.”
In the end, Dr Velsaco said, cannabinoids “may be part of the cocktail that is used to treat some patients.”
But the real-world market dynamics limiting the financial support for clinical trials, he said, adds to the exasperation and confusion of patients who see those benefits proclaimed on the Internet.
Everything takes time and money and a lot of investment,” he said. “I always say that the timing for science and the timing for patients are completely different. When one looks at it from the perspective of science, at least we are moving forward. But if one looks at it from the perspective of a patient who may need this kind of treatment that is not offered to him or to her, then it is frustrating.”
Yet, for now, the FDA makes its position clear:
“We don’t let companies market products that deliberately prey on sick people with baseless claims that their substance can shrink or cure cancer and we’re not going to look the other way on enforcing these principles when it comes to marijuana-containing products,” said FDA Commissioner Scott Gottlieb, MD, in announcing the latest round of warnings. “There are a growing number of effective therapies for many cancers.
“When people are allowed to illegally market agents that deliver no established benefit they may steer patients away from products that have proven, anti-tumor effects that could extend lives.”
- FDA warns companies marketing unproven products, derived from marijuana, that claim to treat or cure cancer [news release]. Silver Spring, MD: US Food and Drug Administration; November 1, 2017. https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm583295.htm?utm_campaign=11012017_PR_FDA%20warns%20companies%20marketing%20marijuana%20 cancer%20products&utm_medium=email&utm_source=Eloqua. Accessed December 2017.
- Cannabis and cannabinoids (PDQ®)–health professional version. National Cancer Institute website. https://www.cancer.gov/about-cancer/treatment/cam/hp/cannabis-pdq. Updated November 30, 2017. Accessed December 2017.
- Maida V, Daeninck PJ. A user’s guide to cannabinoid therapies in oncology. Curr Oncol. 2016;23(6):398-406. doi:10.3747/co.23.3487
- Munson AE, Harris LS, Friedman MA, Dewey WL, Carchman RA. Antineoplastic activity of cannabinoids. J Natl Cancer Inst. 1975;55(3):597-602.
- Abrams DI. Integrating cannabis into clinical cancer care. Curr Oncol. 2016;23(suppl 2):S8-S14. doi:10.3747/co.23.3099
- Guzmán M, Duarte MJ, Blázquez C, et al. A pilot clinical study of Δ9-tetrahydrocannabinol in patients with recurrent glioblastoma multiforme. Br J Cancer. 2006;95(2):197-203. doi:10.1038/sj.bjc.6603236