NEW YORK (Reuters Health) - A drug developed from toxins of the poisonous jack-o'-lantern mushroom is showing promise in patients with pancreatic cancer who no longer respond to conventional chemotherapy drugs.

Irofulven is derived from illudin-S, a substance found naturally in these mushrooms.

"I think it looks very promising," said Dr. S. Gail Eckhardt, of the University of Colorado, who was involved in initial phase 1 studies of irofulven. "It's a unique (anti-cancer) agent."

In the study, one patient had a good response to the drug, she said. This may not sound like much, but pancreatic cancer is very difficult to treat, she noted.

Patients with advanced pancreatic cancer who do not respond to the standard therapy typically have only 3 months to live. In phase II of the irofulven study, seven of 44 patients have survived at least 6 months, according to information from the University of California, San Diego, where research on the anti-tumor activity of the compound is ongoing.

Irofulven has been shown to work in a unique way, Eckhardt said. While irofulven's mode of action is not entirely clear, tumor cells rapidly absorb it, she noted. Once inside the cell, the drug binds to DNA and protein targets. This binding stops the cells from replicating, and causes the cell to shut down. "It seems to rapidly induce cell death," Eckhardt told Reuters Health.

"It really stands out in its mechanism of action," she continued, explaining that the way the experimental drug works is clearly very different from any other chemotherapeutic agent available for pancreatic cancer.

For now, the drug is only being used in research trials of pancreatic cancer patients who have failed to respond to gemcitabine, Eckhardt said. She noted that the drug is also being investigated by other researchers as a potential therapy to treat ovarian and prostate cancer.

Irofulven is one of the acylfulvene family of drugs currently being developed by MGI Pharma, Inc. of Minneapolis, Minnesota.

　　(From HealthCentral.com)