Melanoma Attacked by Hair of the Dog

Vaccine made from cancer cells prolongs lives

TUESDAY, May 15 (HealthScout) -- Patients with severe, advanced melanoma have had their lives extended by a vaccine made by modifying cells taken from their deadly skin cancer, researchers report.

The vaccine, which already has proved effective against less advanced forms of melanoma, has greatly increased the survival time for patients whose cancer has spread substantially, says Dr. David Berd, professor of medicine at the Jefferson Medical College of Thomas Jefferson University in Philadelphia.

He reported a study involving 37 patients with melanoma that had spread from the lymph nodes to the lungs or other parts of the body. Even with surgery to remove the cancer, more than 80 percent of such patients die within five years.

Nearly 60 percent of the patients given the vaccine after surgery are alive after three years, "a good response for these patients," Berd says. The hope now is that the vaccine will produce extended survival for these and similar patients. "Only time will tell," Berd says.

Berd presented his research Monday at the annual meeting of the American Society of Clinical Oncology in San Francisco.

The vaccine is made by what Berd describes as a unique method. Melanoma cells are taken from a patient and are treated with dinitrophenyl, a chemical that modifies the proteins that are recognized by the immune system. "It is an immunological trick that makes the cells more visible to the immune system," Berd explains.

A previous study showed the vaccine to be effective against less advanced melanoma, in which spread of the cancer was limited to the lymph nodes. Two months ago, Berd reported on a study of 214 patients whose cancers had spread to one or two lymph nodes. The five-year survival rate for those patients is nearly 50 percent, and some patients are alive 10 years after receiving the vaccine, Berd says.

Berd's group is taking part in a study aimed at getting Food and Drug Administration approval of the vaccine. Sponsored by AVAX Technologies, Inc., of Kansas City, Mo., it will include 400 patients at several medical centers. "We hope it can be commercialized in several years," Berd says.

The vaccine now is commercially available in Australia, where regulations for approval differ from those in the United States, he says. Australia also has the world's highest rate of skin cancer.

Similar approach to lung cancer

A different way of modifying cancer cells is being used in a vaccine for treatment of another deadly tumor: lung cancer.

"We take cells from a patient and put in a gene to achieve a change in immune expression," says Dr. John Nemunaitis, director of molecular research at U. S. Oncology in Dallas. "It is a whole new approach in immunoinfectivity. It induces intense attraction of the immune system's dendritic cells."

Those cells travel to the lymph nodes, where they stimulate production of lymphocytes and other cells that attack the cancer.

The GVAX approach (so called because the vaccine uses a gene for a G protein) is being tried against cancers of the pancreas and prostate, Nemunaitis says. He described a trial including 22 patients with advanced lung cancer in which other treatments had failed. Typically, those patients have a life expectancy of six months or less.

"We got a complete response in three patients, one partial response and two mixed responses," Nemunaitis says. "In the other four, the cancer stopped progressing."

Cell Genesis, Inc., the San Francisco company that makes the vaccine, is modifying the manufacturing technique for expanded trials in five medical centers, he says. The modification is designed to increase the response rate.

Nemunaitis also made his research public Monday at the oncology meeting.

What To Do

Both melanoma and lung cancer can be prevented by simple measures: Staying out of the sun and protecting the skin with a potent sunscreen for melanoma, and avoiding tobacco for lung cancer. Prevention is always better than treatment.

The Memorial Sloan-Kettering Cancer Center has more information about melanoma and lung cancer.

Read past HealthScout articles about melanoma and lung cancer.

If you're interested in clinical trials for lung cancer, visit Veritas Medicine.

SOURCES: Interviews with David Berd, M.D., professor of medicine, Jefferson Medical College, Philadelphia, and John Nemunaitis, M.D., director of molecular research, U.S. Oncology, Dallas; American Society of Clinical Oncology
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