Researchers at Boca Raton Regional Hospital’s Marcus Neuroscience Institute (MNI) are one of only four sites nationally to be investigating the effectiveness of using engineered polio virus in the treatment of patients with an aggressive brain tumor – glioblastoma (GBM) multiforme – that has been refractory to conventional chemotherapy and/or radiation.
The Federal Drug Administration has designated the trial as “breakthrough therapy” which is meant to expedite the development of medications that have shown preliminary signs of clinical efficacy in patients in early clinical studies.
According to Frank Vrionis, MD, Ph.D., Director of MNI and Principal Investigator for the trial at the Institute, the modified polio virus (called PVSRIPO) is based on the oral poliovirus vaccine used in the U.S. in the past for standard vaccination of infants.
PVSRIPO doesn’t cause polio, but infects different cell types present in brain tumors, including malignant cells and immune cells that infiltrate the tumor. “When induced at the tumor site, it directly kills tumor cells and elicits inflammatory events that engage the immune system,” said Dr. Sajeel Chowdhary, Director of Neuro-Oncology at MNI and Sub-Investigator for the study.
Therapy for patients with brain tumors has always been impeded by what is known as the blood-brain barrier, which blocks chemotherapy agents from reaching tumor sites. The breech of that barrier through neurosurgical technique has now changed everything. “Through the use of micro catheters under MRI guidance and using a technique called convection enhanced delivery, we can now bypass the blood-brain barrier and deliver the therapeutic agent, such as PVSRIPO, to the tumor site” said Dr. Vrionis.
The procedure itself is minimally invasive and usually requires a one to two day hospitalization.
Findings of the use of PVSRIPO in the treatment of patients with recurrent GBMs have been very encouraging. Today, The New England Journal of Medicine published clinical trial results conducted by The Preston Robert Tisch Brain Tumor Center at Duke – Duke authors treated 61 patients with recurrent malignant gliomas with recombinant poliovirus infusion and noticed a 21 percent chance of three year survival versus four percent in historical controls.
“The use of immunotherapy in the treatment of cancer patients is now the new frontier in oncology,” noted Dr. Vrionis “We’re most proud that MNI has joined such a prestigious group in advancing the boundaries of that frontier.”