UB Researcher Secures $3.2 Million NCI Grant to Investigate Cannabis’s Impact on Immunotherapy Treatments

Rebecca Ashare, PhD, an associate professor of psychology at the University at Buffalo, has been awarded a substantial $3.2 million grant from the National Cancer Institute (NCI). The grant aims to explore how the use of cannabis influences patients undergoing immunotherapy, an advanced cancer treatment that harnesses the immune system's power to combat cancer.

Immunotherapy, notably a subtype involving immune checkpoint inhibitors (ICIs), is administered to nearly 44% of cancer patients across 20 different tumor types. Immune checkpoints are a natural aspect of the immune system that regulate immune responses to protect healthy cells from destruction.

Approximately 40% of cancer patients report using cannabis for symptom management during and after their treatments. However, there's a dearth of rigorous research on the effectiveness and potential risks of using cannabis in this context, according to Dr. Rebecca Ashare, who serves as the principal investigator for the grant and is an associate professor of psychology at the UB College of Arts and Sciences.

Dr. Ashare stated, “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.”

Immune checkpoint inhibitors are a common form of immunotherapy used as a frontline treatment for cancer. They generally entail fewer side effects compared to chemotherapy and allow patients to receive treatment over a longer duration. However, cannabis possesses anti-inflammatory properties that can suppress immune function, potentially compromising the effectiveness of immunotherapy.

Dr. Ashare notes, “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 grant involves collaboration with multiple partners. Thomas Jefferson University and Oregon Health and Science University will join UB in recruiting participants for a 12-month observational study conducted at three sites. The study aims to advance the understanding of the long-term benefits and risks of cannabis use among cancer patients receiving immunotherapy.

Each site will recruit 450 participants undergoing cancer treatment with ICI immunotherapy, divided equally between cannabis users and non-users. Dr. Roberto Pili, an MD and the 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 the Great Lakes Cancer Care Collaborative.

Participants will not be randomized, and they will utilize their own cannabis products. The research team will assess the benefits and potential risks through medical records, patient outcomes, and blood samples taken at six different intervals over a one-year period.

This project is part of an NCI-funded consortium that constitutes the largest study in the country to investigate cannabis use in cancer patients.

In addition to examining the impact of cannabis use on cancer patients, the grant also seeks to explore the role of neighborhood disadvantage in relation to cannabis use and ICI immunotherapy outcomes. Dr. Ashare emphasized the desire to assess whether access to cannabis can reduce health disparities.

Dr. Ashare's work in the realm of cannabis use by cancer patients started several years ago, initially focusing on whether cannabis could serve as an opioid-sparing agent, enabling patients to reduce their opioid dosage while effectively managing pain. During this research, it became evident that a significant knowledge gap existed regarding the potential side effects and adverse effects of cannabis use in this context.

Dr. Ashare believes the time has come to address this gap in our understanding, stating, “We have a strong multidisciplinary team with expertise in cancer symptom management, medical cannabis, health equity, oncology, immunology, and substance misuse. Overall, this research will have a sustained impact on the science of cancer symptom management and ultimately improve patient care and safety.”