Scientists at UCLA Health Johnson Comprehensive Cancer Center have developed a new cytokine-enhanced CAR-T cell therapy that improves the immune system’s attack on aggressive brain tumors in mice, while reducing the dangerous side effects that have long limited immune-based treatments for glioblastoma, one of the deadliest and most treatment-resistant brain tumors.
This therapy works by reprogramming CAR-T cells to release immune-stimulating proteins called IL-12 and DR-18, which activate the body’s own immune system and enhance the overall anti-cancer response. In mouse models, this approach has improved tumor control, including cancers composed of mixed cell populations that often escape treatment. The researchers also found that combining the treatment with a second CAR-T strategy that targets VEGF, a protein that promotes abnormal blood vessel growth and contributes to glioblastoma swelling, can reduce side effects while maintaining strong antitumor activity.
The findings, published in Cancer Research, a journal of the American Association for Cancer Research, suggest a potential new strategy for treating recurrent high-grade gliomas and other solid tumors that have been difficult to target with CAR T-cell therapy.
why is it important
Glioblastoma remains extremely difficult to treat because the tumor suppresses the immune response, contains diverse cancer cells, and produces abnormal blood vessels that limit the effectiveness of immunotherapy. CAR-T cell therapy has revolutionized the treatment of certain blood cancers, but success in solid tumors has been limited.
A key challenge in the treatment of brain tumors, particularly glioblastoma, is that tumor cells are often antigenically heterogeneous. This means that they do not all express the same proteins that can be recognized by specific targeted therapies. We hypothesized that effective immunotherapy for brain tumors requires combating cancer with naturally occurring immune cells that can recognize a variety of target antigens. ”
Dr. Yvonne Chen, co-director of the Tumor Immunology and Immunotherapy Program at UCLA Health Johnson Comprehensive Cancer Center and senior author of this study
what happened in the research
Because brain tumors are thought to be immunologically “cold,” meaning they do not naturally provoke a strong immune response, the researchers engineered so-called “armored CAR-T cells” to activate immunity against tumors. These CAR-T cells are built to recognize a tumor antigen called IL-13Rα2, a protein commonly found on glioblastoma cells, while also secreting an immune-stimulating protein that recruits and activates the body’s immune cells.
The team then tested multiple combinations of these “armor” molecules in an immunocompetent mouse model of glioblastoma and used head-to-head comparisons to assess how each design affected tumor growth and immune activation. CAR-T cells have been studied in several orthotopic glioma models, including tumors engineered to have altered antigen expression to better reflect the heterogeneity seen in human disease.
what they found
After testing multiple combinations, the researchers identified one particularly potent combination: IL-12 and decoy-resistant IL-18, known as DR-18.
“IL-12 and DR-18 act synergistically to activate the immune system, resulting in a dramatic influx of immune cells into the brain where tumors reside,” said Chen, a professor of microbiology, immunology, and molecular genetics at UCLA and a member of the UCLA Broad Stem Cell Research Center. “Diverse immune cell populations recruited to the brain contribute to tumor attack, including those that cannot be directly recognized by CAR-T cells themselves.”
Although this therapy has demonstrated the ability to eliminate tumors containing cancer cells lacking targets recognized by CAR-T cells, it remains a major hurdle in glioblastoma treatment because tumors can evolve to evade single-target therapy.
Tackling toxicity
Because IL-12 can cause dangerous inflammation, the researchers also looked for ways to reduce side effects while maintaining antitumor activity.
They found that by adding a second engineered CAR-T approach that targets VEGF, they could reduce treatment-related toxicities while maintaining strong tumor control in mice.
“When developing new treatments, we always need to consider the balance between safety and efficacy,” Chen said. “Because potent cytokines such as IL-12 and DR-18 have potential toxicity, we conducted detailed studies to understand the nature and severity of toxicity and devised a method to address safety concerns while maintaining antitumor activity.”
What this means for patients
This finding suggests a potential new strategy for treating recurrent high-grade gliomas. Researchers are currently completing the preclinical studies and raising the funds needed to begin Phase 1 clinical trials in patients with the disease.
“We are very encouraged that cytokine-armored CAR-T cells have the ability to kill not only tumor cells that express IL-13Rα2, but also tumor cells that CAR-T cells cannot directly recognize,” Chen said. “We are excited to have developed a clinical protocol that allows us to bring this therapy into the clinic while providing a detailed toxicity management plan to ensure patient safety.”
sauce:
University of California, Los Angeles Health Sciences
Reference magazines:
Club, J.D. others. (2026). Armored chimeric antigen receptor T-cell therapy targets antigen-heterogeneity gliomas. cancer research. DOI: 10.1158/0008-5472.CAN-26-1515. https://aacrjournals.org/cancerres/article-abstract/doi/10.1158/0008-5472.CAN-26-1515/785243/Armored-chimeric-antigen-ceptor-T-cell-therapy?redirectedFrom=fulltext
