Thursday, June 19, 2008

Melanoma Study Offers Cautious Hope

By KEITH J. WINSTEIN June 19, 2008; Wall Street Journal, Page D5

Doctors in Seattle cured a late-stage cancer patient after tinkering with his body's defenses against infection, leading to cautious optimism about treating late-stage melanoma, a deadly skin cancer.

The surprising result, published in this week's issue of the New England Journal of Medicine, is the latest hopeful finding from the 30-year-old field of "adoptive immunotherapy," which theorizes that the body can be taught to fight off its own cancers.

Researchers published several promising studies in the 1980s, but translating the findings into successful cancer treatments has been slow. Treatment requires extracting a patient's own white blood cells that are particularly adept at fighting a tumor, breeding the cells in a Petri dish, and then re-injecting them into a patient.

"This is the ultimate personalized medicine, because literally we create a new drug for every patient out of their own cells," said Steven Rosenberg, chief surgeon at the National Cancer Institute, who has published several studies on such treatments. But "it's a labor intensive kind of treatment, and it doesn't lend itself well to commercial development," he said.

Earlier this month, Dr. Rosenberg discussed the results of his experiments at a Boston conference of microbiologists. Out of 93 patients treated, 52 experienced a positive response, Dr. Rosenberg said. At least four patients saw their cancers disappear completely. The complete test results haven't yet been published.

"Pharmaceutical companies have been a little reluctant to pick this up, because they want drugs they can make and put in a vial and sell the vial," Dr. Rosenberg said. "It's very frustrating to me. I lose a lot of sleep over it."

Cassian Yee and other doctors at the Fred Hutchinson Cancer Research Center in Seattle treated a 52-year-old Oregon man with melanoma that had spread to his lungs and groin.

The cancer had persisted even after several doses of chemotherapy, meaning his chances of survival were very slim. But after the researchers injected him with five billion of his own, specially bred white blood cells, the man's cancer disappeared completely and has stayed away for more than two years.

The New England Journal article discusses just one patient, who was the only one out of nine to be cured. The other eight melanoma patients haven't had as positive a response to the treatment, Dr. Yee said.

"This is not something we're going to use to cure a lot of patients. This is one patient," he said. The next step is to "treat a lot more patients and see if this is real," Dr. Yee said. "I think in five to 10 years, this will become much more mainstream."

Dr. Yee's and Dr. Rosenberg's research differs in the particulars.

Dr. Rosenberg's studies have focused on one kind of white blood cell, called "killer T-cells," which attack a tumor. Dr. Yee's study instead looked at "helper" T-cells, which are thought to recognize infections and tumors but mostly summon other cells to do the attacking.

In both cases, treating a patient costs roughly between $30,000 and $50,000 and requires specialized biological equipment that is found in only a few laboratories, making the treatment impractical right now for widespread medical use.

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