Researchers at Jefferson Medical College (JMC) hope to find out if gene therapy will be safe and effective in treating glioblastoma, a form of brain cancer.
Jefferson is among some 40 centers worldwide participating in what is believed to be the first organized international gene therapy trial of any kind. The trial is designed to see if gene therapy can not only delay disease progression, but also improve a patient's quality of life.
Neurosurgeon David W. Andrews, MD, Associate Professor of Neurosurgery, JMC, and his colleagues have already treated three patients, and are hoping to recruit several more.
Glioblastoma multiforme afflicts about 6,500 people a year in the United States, and is the most common and deadliest type of brain tumor. Most patients who receive standard treatment surgery and radiation, and sometimes chemotherapy live for only about a year.
This is the first time researchers are studying a new treatment for newly diagnosed glioblastomas. Earlier studies were on recurrent tumors, which proved resistant to long-term therapy.
"Cancer is a genetic aberration," says Dr. Andrews. "Gene therapy is the treatment of the future for cancer."
What the Treatment Involves
The treatment involves inserting a gene derived from a herpes simplex virus into glioblastoma tumor cells. When introduced during brain surgery, the therapy incorporates the gene for an enzyme, thymidine kinase (TK), into the DNA of actively dividing tumor cells. Patients are subsequently given the anti-viral agent, ganciclovir. The combination of the enzyme and virus destroys cancer cells.
The treatment has tremendous appeal, Dr. Andrews notes.
"Primary brain cancers are very resistant to treatment, and we have thus far achieved only modest palliation with conventional strategies," he says. "Biological therapies have shown some promise. Theoretically, it is a strategy upon which we can build. Traditional therapies surgery, chemotherapy, and radiation are limited in effectiveness."
Current treatments are designed to reduce symptoms, rather than cure the disease, he says.
Still, it may take several months for researchers to see any effects from the new treatment, Dr. Andrews says.
The glioblastoma gene therapy protocol was developed by Genetic Therapy, Inc., a wholly owned subsidiary of Novartis Pharmaceuticals Ltd., East Hanover, NJ. Novartis supports Dr. Andrews' work.