What’s the future look like for brain cancer treatment? Promising, thanks to a growing number of pioneering studies and treatment techniques.
That’s according to University of Minnesota Health Neurosurgeon Clark C. Chen, MD, PhD, who is also chair of the Department of Neurosurgery within the University of Minnesota Medical School.
Glioblastoma is the most common form of brain cancer. There are several reasons why these brain cancers have been extremely difficult to treat. Many glioblastomas are naturally resistant to the currently available chemotherapies. Others quickly adapt to the effects of these therapies. These factors and others have kept the long-term survival for certain brain cancers as low as 5 percent, according to the National Cancer Institute.
However, Chen believes new clinical trials and research are a cause for optimism.
“From the past five decades of research, we have learned that brain cancer cells quickly adapt to the chemotherapies that we administer. To meaningfully disrupt these adaptations, we need to activate and program the patient’s immune system—to create ‘counter-moves’ against each of the cancer adaptations. We now have several clinical trials that aim to achieve this end.”
Here are four promising therapies that are available at University of Minnesota Health:
Immunotherapy is treatment that activates a part of the body’s natural immune system to fight diseases, including cancer. A recently developed immunotherapy drug combination may prove to be an effective treatment for glioblastoma.
Toca 511 is an engineered virus that selectively infects glioblastoma cells. The virus is injected directly into the patient’s brain following surgery to remove the bulk of the tumor. Once the virus has replicated and spread throughout the remaining cancerous cells, the patient is given Toca FC, a follow-up drug. Toca FC combines with Toca 511 to destroy the infected cancer cells. The reaction also activates the body’s immune system, which then helps prevent the cancer cells from growing back.
Clinical trials using Toca 511 and Toca FC show exceptional promise, Chen said. In the studies, where enrolled patients are expected to live 4-9 months, 20 percent of patients treated with both survived three or more years. Because of the results, Toca 511 and Toca FC have received a “Breakthrough Therapy” designation from the Food and Drug Administration (FDA)
The clinical trial is currently available to brain tumor patients at the University of Minnesota.
University of Minnesota Health physician researchers are testing whether immunotherapy can be effective against brain cancer when combined with a genetically engineered form of the virus that causes the “common cold.”
The drug therapy, developed by DNATrix, is also injected during surgery to remove a brain tumor. The virus in the drug targets cancer cells’ natural vulnerabilities and triggers inflammation where those cells reside in the body. After surgery, the patient is treated with state-of-the-art immunotherapy that wipes out the remaining brain tumor cells. Early studies show this drug boosted the three-year survival to 20 percent.
“Both the Toca511 and the DNATrix virus exert their effects specifically on the brain tumor cells,” Chen said. “For this reason, we observed very little toxicity from these therapies. By treating our patients with these selective therapies, we preserve the quality of life for our brain tumor patients.”
It sounds like science fiction, but this emerging therapy is a promising approach to killing brain cancer.
Laser ablation surgery uses a laser to heat and destroy cancerous tumors. The heating effects of the procedure are monitored in real time using magnetic resonance imaging (MRI) to avoid injury to nearby healthy brain tissue. This procedure can be carried out through a small incision the size of a pea. Patients are discharged from the hospital the day after surgery, typically without the need for pain medication. The heat from laser ablation therapy also activates the body’s immune system, which in turn increases the body’s innate ability to fight brain cancer.
Chen and colleagues are planning a clinical trial—Laser Ablation of Abnormal Neurological Tissue (LAANTERN) to explore this relationship in greater detail.
Cancer researchers have already developed vaccines to treat cervical and prostate cancer. Now, University of Minnesota Health physician researchers are exploring whether a similar vaccination strategy may be effective against brain tumors.
Their efforts have focused on a molecule called CD200. CD200 is a protein produced by brain tumors that helps the cancer cells hide from a body’s immune system. Researchers from the Masonic Cancer Center, University of Minnesota have discovered that vaccines prepared from protein fragments of CD200 can reverse this process and program the patient’s immune system to fight off brain cancer. A clinical trial using CD200 is expected to open for patient enrollment in 2019.
“For every adaptation that cancer cells make to cancer treatment, the immune system is capable of creating a ‘counter-move’,” Chen said. “Engaging this living, dynamic immune system will be key to ultimately curing brain cancer.”