Researchers Net $3.2M Federal Grant to Study How Cannabis Affects Patients Who Receive Immunotherapy

A University at Buffalo (UB) researcher has been awarded a $3.2 million National Cancer Institute grant to study how cannabis affects patients who receive immunotherapy. According to Rebecca Ashare, PhD, associate professor of psychology in the UB College of Arts and Sciences and the grant’s lead investigator, up to 40% of cancer patients report using cannabis for symptom management during and after immunotherapy treatments, but there isn’t much rigorous research investigating the efficacy of using cannabis for that purpose. 

“There are virtually no long-term studies evaluating its potential benefits and harms for persons treated with immunotherapy for cancer, despite cancer and its treatments being qualifying conditions in most of the 37 states and Washington, D.C., that have legalized adult use or medical cannabis. There are reports of benefits surrounding pain relief, improving mood and curbing sleep deprivation, but there is also evidence of physical, cognitive and mental harms, including cannabis use disorder.” — Ashare in a press release 

Nearly 44% of cancer patients with 20 different tumor types receive immunotherapy treatment; notably, a specific type involving immune checkpoint inhibitors (ICIs). Immune checkpoints are a normal part of the immune system that govern the immune response to prevent the destruction of healthy cells. 

“The demand for evidence is clear and this project represents an important first step in that process as both immunotherapy and cannabis use are becoming more widespread therapeutic options in oncology, accepted by many patients and physicians,” Ashare said in a statement. 

In general, ICIs have fewer side effects than chemotherapy, and patients can be on the treatment longer than chemotherapy, but cannabis has anti-inflammatory properties that can suppress immune function, which Ashare said is “usually a good thing, except when you want the immune system to be active in order to fight cancer; so there are concerns that cannabis might reduce the efficacy of immunotherapy.”

Thomas Jefferson University and Oregon Health and Science University will join UB in recruiting participants for the three-site, 12-month observational study to advance research regarding the benefits and harms of cannabis use over time among cancer patients treated with immunotherapy. Each site will begin recruiting 450 participants being treated for cancer with ICI immunotherapy – half of the participants will be cannabis consumers and the other half will be non-consumers. Participants are not randomized for the studies, and each will use their own cannabis products. The research team will assess benefits and harms through medical records, patient outcomes, and blood samples at six different times over a one-year period.