Temple University Health Sciences Center
Contact: Andrew Smith, (215) 707-8229
Experimental Treatment Being Tested for Malignant Brain Tumors
PHILADELPHIA -- Using a genetically engineered toxin that is delivered directly into a patient's brain tumor, physicians at Temple University Hospital hope to shrink or eradicate malignant brain tumors that return after standard treatment.
Despite technological advances, malignant brain tumors invariably progress or regrow after surgery, radiation therapy or chemotherapy. There are no good treatment options for such tumors. There are a variety of reasons for this. The patient's tumor may have spread and may be inoperable or the patient's brain can't tolerate more radiation.
Temple's Department of Neurosurgery has initiated a Phase II, multicenter trial for the treatment of these tumors using the experimental drug, HN-66000. Temple is the only hospital in the Delaware Valley and one of only 10 in the country that is conducting the trial.
"HN-66000 consists of two parts," says Dr. Doug Laske, director of Temple's Brain Tumor Program and one of the study's primary investigators. "The first is a binding protein which recognizes and attaches to tumor cells. The second part of the toxin is a modified diphtheria toxin (the toxin has been altered so it won't cause diphtheria). The complete compound can selectively kill tumor cells."
The targeted toxin showed promise during a Phase I trial performed at the National Institutes of Health and completed in 1995 -- a trial Laske and his co- investigators initiated.
During the Phase II trial, patients will have two thin, plastic tubes inserted through the skull and into the tumor. The tubes can be exactly placed thanks to a three-dimensional "map" of the brain that's created by CT or MRI. After the tubes are placed, they are connected to syringes containing the toxin. The toxin is then slowly infused directly into the tumor over a period of five to seven days. The tubes are then removed. Four to six weeks later, the patient returns for a second treatment.
The first patient to participate in the trial completed his first treatment on January 19 and is scheduled for his second treatment on February 17. A second patient will receive his first treatment on February 6.
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