Gene Therapy Doubles Survival in Recurrent Glioblastoma
VIENNA, AUSTRIA—An experimental gene therapy essentially doubled the overall survival of patients with recurrent glioblastoma compared with the current standard of care, a researcher said at 2015 European Cancer Congress.
Glioblastoma is an aggressive brain cancer that kills two-thirds of patients within 5 years. A patient's prognosis with recurrence of the disease is considered to be weeks or months.
The presentation discussed the final results of a phase 2 clinical research that evaluated the gene therapy VB-111 in continuous and intermittent doses and in comparison with the treatment standard, bevacizumab. The findings were presented by Andrew J. Brenner, MD, PhD, associate professor in medicine, neurology and neurosurgery at the Cancer Therapy & Research Center (CTRC) at The University of Texas Health Science Center at San Antonio.
Patients receiving VB-111 survived 15 months on average, compared with 8 months on average for patients receiving bevacizumab. The CTRC and three other centers enrolled 62 patients with recurrent glioblastoma for the studies.
"These are the patients with the most serious cases, whose glioblastoma has recurred after surgery and who, as a result, have a very short life expectancy," Brenner said.
"In addition to the benefit in overall survival, VB-111 was safe and well-tolerated in the patients, and proved to be effective both as a single therapy for recurrent glioblastoma and in combination with Avastin [bevacizumab]," Brenner said.
VB-111 effectively starves the tumor by blocking its ability to grow new blood vessels, Brenner said. Tumors themselves begin the process by secreting a factor that activates the VB-111 drug. "This drug outsmarts the cancer," Brenner said.
VB-111 is administered by intravenous infusion once every 2 months, which is convenient for patients and families. VB-111 has orphan drug status in the United States and Europe.
The most frequent side effect in the study was fever, lasting 1 to 2 days following infusion. This suggests an immune system response to the drug, which may play a role in its effectiveness, Brenner said.
The improvement in overall survival is clinically significant. "These numbers compare favorably to any current benchmark in recurrent glioblastoma and may change the treatment paradigm for these patients," Brenner said.
Phase 2 studies, conducted after first-in-human studies, add detail about the effectiveness and safety of experimental treatments for disease. VBL Therapeutics of Tel Aviv, Israel, maker of VB-111, recently launched a Phase 3 clinical research study of the drug to provide more detail.
The CTRC is currently the only site open for the Phase 3 trial, with the first patients enrolled in San Antonio. Approximately 50 more sites in North America, Israel, and Canada will be added in November 2015.