Sept. 19, 2002 -- Like a revved-up engine that breathes new life into a worn-out clunker, a promising new cancer treatment may revive a disease-ravaged immune system and turn it into a cancer-fighting machine.
In the first major test of the treatment in people with a deadly form of melanoma (skin cancer), six of 13 patients had a significant shrinkage of their cancer and another four saw at least some cancer growths disappear. None of the patients had previously responded to even the most aggressive treatments currently available.
Researchers say the innovative, two-step approach designed to boost the body's own natural defense system may also lead to new treatments for other types of cancer as well as infectious diseases, including AIDS, by helping the body better fend off attacks.
Until now, the main problem with these therapies has been an inability to sustain high enough levels of infection-fighting immune cells long enough to make the disease go away. But by modifying how the immune cells are generated in the laboratory and how people receive them, researchers were able to produce highly focused immune systems that can seek out and destroy cancer cells from the inside.
"Nothing like this has ever even been approached before in humans," says study researcher Steven A. Rosenberg, MD, PhD, chief of surgery at the National Cancer Institute. "It's a technique that generated staggeringly high numbers of immune cells, and the patients reacted against the cancer."
Rosenberg presented the research today in Washington at a briefing sponsored by the American Medical Association. The study appears in the October issue of Science.
Nancy H. Nielson, MD, PhD, member of the AMA's board of trustees, calls the findings "earth shattering" and says they should give hope to thousands of cancer patients.
Rosenberg says there are two main differences between this new two-step technique and previous unsuccessful approaches.
First, researchers temporarily shut down and eliminated the body's own ineffective immune system using chemotherapy. Then, the patients received an infusion of highly selective anti-cancer cells derived from the patient's own tumor.
Once these specialized, infection-fighting cells are in the body, they continue to divide and multiply. Meanwhile, the patient's own immune system continues to replenish itself and function as normal.
Rosenberg says the findings are important because researchers were not only able to generate enough of these cancer-fighting cells to launch an attack, but those levels were sustained for up to five months -- allowing the battle to continue.
Although the researchers emphasize that these findings are only preliminary and the treatment has only been tested in 13 patients, they plan to start new studies in cancers other than melanoma within the next few months.
Three of the patients tested did not have any response to the therapy. The researchers are trying to determine who might be the best candidates for this new treatment.
While the immune system is suppressed, there is also an increased risk of infection to the patient. But researchers say they saw only minor, treatable infections in this study. -->