Florida Researchers Find New Drug Delivery System Prolongs Life For Some Cancer Patients

May 17, 1996

GAINESVILLE—A new, cost-effective method of delivering potent cancer drugs to patients whose cancer has spread to the brain is enabling them to live four times longer, University of Florida researchers reported today (5/17).

This allows scientists to attack brain cancer more aggressively with fewer side effects — an advantage they hope will someday improve treatment for all cancer patients.

At the annual meeting of the American Society of Clinical Oncology, UF physicians released data from a study of patients who received the drugs through a novel delivery system.

Administering cancer drugs by encapsulating them in microscopic foam particles — similar to the way a sponge traps water — reduces toxic side effects and prolongs drug levels in the body. Researchers at the University of California-San Diego developed the technology. The foam vesicles are constructed of fats and amino acids that resemble a normal cell membrane.

UF researchers who studied 32 patients treated at the UF Shands Cancer Center found that average survival increased from 68 days for patients receiving standard treatment to 277 days for those receiving the experimental treatment, without any increase in side effects or toxicity.

“That’s a tremendous impact,” said Dr. Bernard Maria, chief of neuro-oncology at UF’s College of Medicine and UF’s principal investigator of the study. “It’s so rare that you try something new like this and see such a striking improvement in outcome. Cancer is hard to beat, and once it has spread to the surface of your brain the prognosis is not good. Tumor cells get into places where they are hard to reach without using treatments that damage the nervous system. We’ve been limited in how aggressive we can be, but this new approach is going to change that.”

Typically, physicians give patients whose cancer has spread to the brain or spinal fluid cancer-fighting drugs by spinal tap, or through a catheter directly into the fluid that bathes the brain. Doses are given several times a week for a month, then slowly tapered over a period of weeks.

But because drug levels rapidly peak, then quickly drop, physicians must repeat doses frequently to maintain the amount needed to kill tumor cells. Doing so gives some patients headaches, nausea or low blood counts.

With the new “Depofoam” encapsulated delivery system, drugs slowly leak into the cerebrospinal fluid, prolonging levels high enough to kill cancer cells while reducing side effects and cutting back on the need for multiple injections.

Researchers also showed that the new drug delivery system was less costly. Depending on whether the drugs were injected through a reservoir into the brain or through a catheter into the spinal fluid, the method saved $2,804 or $7,376, respectively. And because fewer injections were required, the regimen saved $467 or $1,229 per injection, again depending on how the drugs were injected.

“In this day and age, insurers not only expect new products to be safe, nontoxic and effective, but also cost effective,” Maria said. “We showed that because the drug could be given less frequently than standard treatment, the new system is cheaper. So it’s an all-around winner. And for solid tumors like breast, lung and skin, which can spread to the spinal fluid, there is no question this can help improve the outlook for patients with this kind of cancer complication.”

Patients enrolled in the study all had a condition known as carcinomatous meningitis, which occurs when cancerous cells spread from a tumor located in places like the brain, lung or breast. Some patients with melanoma, leukemia and lymphoma also develop this form of meningitis.

UF researchers tracked patients older than 3 for the multicenter study, which is continuing in the United States and Canada. A computer was used to randomly select which patients would receive the encapsulated form of the drug.

Depofoam Encapsulated Cytarabine was developed by researchers at the University of California-San Diego and is manufactured by DepoTech Inc., based in LaJolla, Calif.

The UF Shands Cancer Center is the outpatient component for clinical services for cancer patients at the University of Florida and Shands Hospital.