Physicians at the John Theurer Cancer Center (JTCC) at Hackensack University Medical Center have announced their involvement in a promising multicentre phase 1 study assessing the safety and tolerability of Toca 511 in patients with glioblastoma, the most common and lethal form of brain cancer. Toca 511 is a retroviral replicating vector that has been engineered to deliver a therapeutic gene selectively to brain tumour cells while sparing healthy brain tissue.
In this study, sponsored by Tocagen Inc, Toca 511 is injected directly into the brain tumour through a stereotactic biopsy needle. Once injected, Toca 511 infects tumour cells, sparing healthy functioning brain cells. During the following weeks, patients are then given cycles of an oral medication, 5-flucytosine (5-FC), an antifungal drug that readily enters the brain. The infected tumour cells now carry genetic instructions for an enzyme that converts 5-FC into 5-fluorouracil (5-FU), a highly-potent chemotherapy that destroys cancer cells, which may lead to activation of the immune system against the tumour.
“Over the past 40 years, we have seen new developments for glioblastoma, but none that have successfully improved the long-term outlook for our patients. One of the main challenges to finding a breakthrough is the difficulty of delivering chemotherapy across the blood-brain barrier,” says Samuel A Goldlust, medical director, Brain and Spine Institute at JTCC. “The infective power of viruses has evolved over millions of years. By using that power to infect and destroy brain cancer, we hope to make a significant impact upon survival.”
JTCC is one of only 10 institutions across the USA involved in this study, and the only site in the northeast. “The clinical trial allows us to offer patients a less invasive procedure compared to traditional surgery, and most patients are able to return home the next day,” says George J Kaptain, surgical director, Brain and Spine Institute at JTCC.
Currently ongoing, the study will enrol up to 50 patients with glioblastoma and other aggressive high-grade gliomas (Grade 3 or 4) who have already undergone surgery, radiation therapy and chemotherapy. Among the estimated 13,000 new cases of high-grade glioma each year in the United States, glioblastoma is the most common and aggressive, with only five percent of patients surviving to five years after diagnosis.