The Arizona Daily Star

Published: 09.01.2006

Gene therapy successfully treats melanoma
By Jeff Nesmith
COX NEWS SERVICE
local angle
Although the University of Arizona Cancer Center has not been involved in this particular melanoma study, Immune- system therapies for this deadly skin cancer have been the focus of research here for decades. In fact, a trial testing a very similar type of immune- cell manipulation was just concluded at the cancer center, said Dr. Lee Cranmer, a UA melanoma specialist.
That study involved harvesting a different type of immune-system cell, known as dendritic cells, from the cancer patient, programming them in the test tube to attack melanoma cells, then infusing them back into the patient. The UA tested this approach on two patients with advanced melanoma, as part of a national study involving 37 patients. Preliminary results are expected within three to six months, Cranmer said.
WASHINGTON — Government scientists revealed Thursday that they had successfully used genetic engineering to train the white blood cells of two melanoma patients to attack and destroy the cancer.
The experiment failed to help 15 other melanoma patients.
However, it represents a proof of the principle that gene therapy can be used to successfully treat cancer, other scientists said.
Plans are under way to expand the experiment with efforts to treat breast and lung cancer, said Dr. Steven Rosenberg, the National Cancer Institute researcher who directed the melanoma experiment.
By inserting a gene that enabled the white cells to recognize melanoma, the NCI scientists caused the cells, known as lymphocytes, to swarm through the bodies of two men, finding cancer cells and destroying them.
The two patients have been cancer-free for nearly two years, even though the cancer had metastasized throughout their bodies when the treatments were begun.
The experiment represents a personal victory for Rosenberg, a surgeon and biophysicist who has spent nearly two decades searching for a way to turn the human immune system against cancer.
If the success rate can be increased and applied to other types of cancer, the use of genetically modified lymphocytes would be an entirely new approach to treating the disease.
"This may be the most important paper I have ever written," said Rosenberg, whose team describes the new treatment today in the journal Science.
He said lymphocytes — sometimes called "killer cells" because they attach themselves to diseased cells and destroy them — normally do not attack cancer because the body does not program them to recognize cancer cells.
His team implanted a gene that does recognize melanoma into white cells taken from the patients' own blood, grew billions of the genetically changed cells in a laboratory, then re-injected them into the patients.
"These results represent the first time gene therapy has been used successfully to treat cancer," said Dr. Elias Zerhouni, director of the Cancer Institute's parent agency, the National Institutes of Health.
"Moreover, we hope it will be applicable not only to melanoma but also for a broad range of common cancers, such as breast and lung cancer," he added.
Rosenberg said he is awaiting Food and Drug Administration approval to attempt the treatment on lung- and breast-cancer patients with lymphocytes that have been changed to recognize those forms of cancer.
The melanoma experiment caused Mark Origer, the 53-year-old postmaster of Watertown, Mass., to become one of the Cancer Institute's most ardent supporters.
"I am so thankful that place is there and that there are brilliant minds working on these problems," said Origer, one of the two patients in whom the treatment succeeded.
He said his frightening struggle with melanoma began in 1999, when his wife noticed a small, dark mole between his shoulder blades.
A biopsy showed it contained melanoma cells. Despite repeated operations and chemotherapy treatments, the cancer spread, he said.
local angle
Although the University of Arizona Cancer Center has not been involved in this particular melanoma study, Immune- system therapies for this deadly skin cancer have been the focus of research here for decades. In fact, a trial testing a very similar type of immune- cell manipulation was just concluded at the cancer center, said Dr. Lee Cranmer, a UA melanoma specialist.
That study involved harvesting a different type of immune-system cell, known as dendritic cells, from the cancer patient, programming them in the test tube to attack melanoma cells, then infusing them back into the patient. The UA tested this approach on two patients with advanced melanoma, as part of a national study involving 37 patients. Preliminary results are expected within three to six months, Cranmer said.

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