City scientists planning trials of drug to fight brain tumors

By Heather Warlick

Published: July 1, 2008

Oklahoma scientists have made great strides lately in the fight against brain tumors, but those advances may not be commercially viable in time to help Sen. Edward Kennedy in his life-and-death battle.

When Kennedy was diagnosed with a malignant brain tumor in May, he put on a brave public face, flashing an optimistic "thumbs up” at reporters and stating he is ready for a fight even though he knows the prognosis for such tumors is grim.

His biopsy revealed that he suffered from a malignant glioma in the left parietal lobe of his brain. A glioma is a brain tumor that begins in the glial, or supportive cells of the brain or spinal cord. These tumors can grow to occupy as much as 25 percent of the brain. Generally, treatment methods can extend the life of patients but not cure the cancer.

Since his cancer diagnosis, Kennedy has undergone surgery to remove the tumor, and his doctors will proceed with radiation and chemotherapy. This course of treatment is the most common and widely used treatment for gliomas.

According to the American Cancer Society, more than 21,000 Americans will develop brain and nervous system cancers this year. About 13,000 people will die from these conditions.

Though the work of two Oklahoma City scientists may be too late for Kennedy, the scientists' findings could greatly improve the prognosis for future glioma patients.

Robert Floyd and Rheal Towner, both of the Oklahoma Medical Research Foundation, may have identified a compound that can halt brain tumors such as Kennedy's. The compound has proved successful at reducing the rate of growth and even eradicating glioma tumors in about 90 percent of animal trials.

"The compounds we're working on show unusual promise,” Floyd said. "The mechanism, well, we don't know exactly why this works yet. It seems to have action in sort of shutting down angiogenesis.”

For a tumor to grow, it needs blood vessels to form, supplying fresh blood and oxygen, a process called angiogenesis. Floyd and Towner's compound seems to prevent this process from occurring, thereby robbing the tumor of oxygen and killing it. Floyd said the compound has similar effects in liver tumors.

"The chemicals show potency in many different models in age-related diseases. I would not be interested unless they had very potent biological activities,” Floyd said. "We're just trying to see if they have some value in human beings.”

The compound is already known to be nontoxic to people, a fact that was learned from previous large-scale clinical trials with a different focus. It can be orally administered and taken at home.

There is usually a period of several weeks between the time a patient is diagnosed with a glioma and surgery to remove it, if surgery is an option. Floyd and Towner said they hope the compound, if it eventually is made into a viable drug, can be administered as soon as the diagnosis is made. Floyd said it begins working immediately, so it ideally would isolate the tumor from the surrounding blood vessels that are supplying it with sustaining oxygen and make its removal easier and more complete. Then the compound would continue to be administered during radiation and chemotherapy.

"We found that if we actually treated an animal with this compound before we initiated the cancer process that we can actually prevent the initial process of cancer from occurring,” Towner said.

Floyd and Towner have formed a biotechnology company called Oconos with the near-term focus of conducting clinical trials on the compound and a long-term goal of obtaining federal approval for the drug's use in treating gliomas.

They estimate that human trials could begin in about a year. If all goes well, the drug could receive FDA approval in four years.

Phase one human trials will likely occur at the University of Utah's Huntsman Cancer Institute.

Oklahoma Medical Research Foundation scientists Robert Floyd, left, and Rheal Towner are researching techniques that they hope will reduce the growth of certain types of brain tumors.

Comments