BOSTON -- Endostatin, a cancer drug discovered by doctors at Children's Hospital in Boston and once touted as a possible cure, has yet to show dramatic benefits after seven months of safety testing.
"I'm not aware of any major clinical response to date," Dr. James Pluda, a senior investigator at the National Cancer Institute, said in today's Boston Globe.
The drug, discovered by Dr. Judah Folkman and his colleagues, is undergoing three separate trials with a starting total of 45 patients. The Cancer Institute is overseeing the tests at Dana-Farber Partners Cancer Care in Boston, the University of Wisconsin at Madison and in Houston.
Folkman reported in 1998 that endostatin, known as an angiogenesis inhibitor, was one of two proteins that caused tumors in rats to shrink or disappear by cutting off their blood supply.
According to the Globe, there have been persistent Internet rumors that the drug has made impressive gains against tumors in test patients.
However, the Globe reported, a number of the patients have dropped out of the trials, although researchers will not say how many.
One of the dropouts was Chuck Killian of Chicago. Tests in Wisconsin showed that his liver cancer had enlarged by 70 percent while on endostatin, and under research rules, a cancer that has grown by 50 percent or more makes the patient ineligible for the drug.
Killian has appealed for doctors to reinstate him in the program on a higher dose of endostatin, but has been turned down.
"If I had evidence at this point that we were having a significant clinical effect (at higher doses), and that the higher doses were safe to give to someone who had received a substantial amount of drug already, I'd feel bad and we would probably try to do something," Pluda said. "But I don't have any such evidence as yet."
Even Folkman said he could not help Killian, because he has no direct control over the trials.
The trials are being sponsored by the National Cancer Institute in Wisconsin, the M.D. Anderson Cancer Institute in Houston and in Boston by EntreMed Inc.
Leaders of the research trials say it is too early to make an official report. They have said informally, according to the Globe, that endostatin appears to have little toxicity, and has shown some activity that suggests it is working as it is supposed to on cells and molecules, but it does not mean it is stopping the cancer.