The American Brain Tumor Association recently hosted a webinar focused on Immunotherapy and Brain Tumors, featuring insights from Dr. Peter Fecci, Director of the Brain Tumor Immunotherapy Program at Duke University. Here’s a breakdown of what immunotherapy is, its potential for treating brain tumors, and why researchers are hopeful.
What is Immunotherapy?
Immunotherapy is a cancer treatment strategy that empowers the body’s immune system to identify and attack cancer cells. Unlike traditional treatments, immunotherapy trains immune cells to detect the unique proteins on cancer cells, allowing for a more targeted and effective attack. By doing so, it can help overcome the body’s natural immune tolerance to these cells.
The Potential for Brain Tumors
Although immunotherapy has had success in other types of cancer, it has been slower to impact brain tumors, particularly glioblastoma (GBM), one of the most aggressive forms. Dr. Fecci highlighted several reasons why GBM remains a challenging target for immunotherapy:
- Heterogeneity of GBM Cells: Brain tumor cells vary widely, making it difficult to target them all with a single treatment.
- Low Mutational Burden: GBM cells generally have fewer mutations than other cancers, offering fewer targets for immune cells.
- Blood-Brain Barrier: This barrier protects the brain but also limits the entry of immunotherapy drugs.
- Immunosuppressive Environment: Brain tumors, especially GBM, create a microenvironment that suppresses the body’s immune response, complicating efforts to launch an effective attack.
Types of Immunotherapies Under Research
Dr. Fecci discussed the main types of immunotherapies being studied:
- Antibody-Mediated Therapy: These therapies use antibodies to block signals that allow tumors to grow or to deliver toxins to tumor cells directly.
- CAR T-Cell Therapy: T-cells from the patient’s blood are modified to recognize and attack brain tumor cells, showing promise for GBM and other complex tumors.
- Oncolytic Viruses: These are engineered viruses designed to infect and kill tumor cells, releasing antigens that stimulate the immune system to attack.
- Checkpoint Blockade: Drugs like pembrolizumab block immune checkpoints (PD-1/CTLA-4), reactivating T-cells to attack the tumor.
Promising Research & Clinical Trials
While immunotherapy for brain tumors is not yet FDA-approved, clinical trials are exploring combinations of immunotherapies. Trials testing combinations of checkpoint inhibitors and other drugs are ongoing to see if this approach can yield better outcomes. Additionally, researchers are hopeful about using Neo-adjuvant immunotherapy, where treatment is administered before surgery, which has shown encouraging early results.
Hope for the Future
The future of immunotherapy in brain tumor treatment looks bright. As research continues, we may see more therapies that combine immune checkpoint inhibitors, CAR T-cell therapy, and other innovative approaches that can bring new hope to patients with brain tumors.
