UB researcher receives $3.2 million grant to study impact of cannabis on immunotherapy

A UB psychologist has received a $3.2 million grant from the National Cancer Institute to assess how cannabis use affects patients who receive immunotherapy, a rapidly advancing treatment that helps the immune system fight cancer.

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. They govern the immune response to prevent the destruction of healthy cells.

Up to 40% of cancer patients report using cannabis for symptom management during and after their treatments. But there isn’t much rigorous research investigating the efficacy of using cannabis for that purpose, according to Rebecca Ashare, associate professor of psychology, College of Arts and Sciences, and the grant’s principal investigator.

“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,” Ashare explains. “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.”

Often used as a frontline treatment, ICIs are a common form of immunotherapy for cancer. In general, they 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.

“That’s 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,” says Ashare. “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.”

The NCI investment in this line of research involves multiple partners.

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 the science regarding the benefits and harms of cannabis use over time among those 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 users and the other half will be non-users. Roberto Pili, associate dean for cancer research and integrative oncology in the Jacobs School of Medicine and Biomedical Sciences, will lead the oncology research for UB and Great Lakes Cancer Care Collaborative.

Participants are not randomized for the studies, and each will use their own 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.

The project is part of an NCI-funded consortium that will include the largest group of cancer patients in the country that has ever looked at cannabis use in patients with cancer.

A second aim of the grant is to examine the role of neighborhood disadvantage on outcomes related to cannabis use and ICI immunotherapy.

“We want to see if access to cannabis reduces health disparities,” says Ashare.

Ashare has been doing work around cannabis use in patients with cancer for a few years, beginning with investigating whether cannabis use could have an opioid-sparing effect, enabling patients to reduce the dosage or amount of opioids they were using while still maintaining effective pain management.

While engaged in that research, it became apparent that there was a lot of work on the potential benefits of cannabis use, but little attention was devoted to potential side effects or adverse effects.

She says now is the time to try to fill in that knowledge gap.

“We have a strong multidisciplinary team with expertise in cancer symptom management, medical cannabis, health equity, oncology, immunology and substance misuse,” says Ashare. “Overall, this research will have a sustained impact on the science of cancer symptom management and ultimately improve patient care and safety.”