City of Hope researchers received approval from the FDA to conduct the first human study of a neural stem cell-based therapy targeting recurrent high-grade gliomas, the most aggressive type of brain tumor. The phase I safety trial will assess the maximum tolerated dose of the therapy and is supported by a grant from the National Cancer Institute, part of the NIH. The clinical trial will begin accepting patients this summer, with the goal of enrolling 12 to 20 patients with recurrent high-grade gliomas.
The modified neural stem cells will be injected during surgery into the wall of the cavity remaining after tumor tissue has been removed. Study patients then receive daily doses of the pro-drug 5-FC for one week. Based on Karen S. Aboody, M.D., associate professor in City of Hope’s research team laboratory findings, once the 5-FC crosses the blood-brain barrier, the neural stem cells will convert the 5-FC to the active chemotherapy agent, 5-FU, at tumor sites in the brain.
An estimated 22,500 Americans are diagnosed with malignant primary brain tumors annually, and more than 12,900 die each year from the disease. While survival rates vary with the type of brain tumor, median survival for glioblastoma, the most common type of glioma in adults, is only about 15 months. These tumors are highly invasive and ultimately resistant to current methods of treatment such as surgery, radiation and chemotherapy. One significant obstacle to curing brain tumors is the presence of the blood-brain barrier which can prevent chemotherapy agents from entering into the brain and reaching effective concentrations at tumor sites.
“This first-in-human clinical trial of a neural stem cell-based therapy that we developed at City of Hope is an investigational, targeted treatment option for recurrent high-grade glioma patients,” said Aboody. “Furthermore, we envision the eventual development of neural stem cells as a platform technology for targeting multiple therapeutic agents to brain tumors, as well as other metastatic solid tumors inside and outside the brain.” “This novel tumor-selective treatment has the potential to overcome many obstacles that limit the success of currently available treatments for malignant brain tumors and other invasive cancers,” said Aboody. “Using neural stem cells as delivery vehicles for therapy may allow us to target concentrated therapeutics specifically to tumor sites while reducing the undesirable side effects of current chemotherapy regimens, including toxicity to normally dividing bone marrow, gastrointestinal tract, skin and hair cells.”