Priming the Body to Tackle Cancer
Immune therapy proves effective against melanoma in an early trial.
Melanoma, one of the most common cancers, is usually treated with surgery and aggressive chemotherapy. In a new, preliminary study, Dr. Marcus O. Butler, of Boston’s Dana-Farber Cancer Institute, suggests a kinder, gentler way of treating melanoma, and perhaps other cancers, using the body’s own defense system.
In a study published in the April 27 edition of Science Translational Medicine, Butler and his colleagues harvested immune cells from nine patients. They souped up the cells in their lab—in effect giving them the ability to remember cancer cells—multiplied them in number, and infused them back into the patients from whom they been taken. This technique, called adoptive t-cell therapy, primes the immune system to seek out and destroy cancer cells throughout the body.
Ten weeks after starting the therapy, seven of the nine patients had more of the specially trained cells than they had started with. The disease in four of the patients had become stable—neither advancing nor retreating. In one patient, the cancer disappeared completely; two years later, it has still not returned.
“We were pleased,” Butler says.
Yee, who also researches adoptive therapy, says cancer doctors tend to push for more-aggressive treatments that save lives but leave patients drained and ill. Butler’s success suggests that equally effective treatments could be developed that are less damaging, he says.
This might be a “good end to the more-is-better” approach, says Yee. “This is really the right way to go, in terms of seeing what minimally is necessary to demonstrate some effectiveness.” Because Butler’s patients were relatively healthy, says Yee, more research will be needed to determine effectiveness in the sickest patients.
The work is not yet ready for commercialization. Laboratory methods for boosting immune cells need to be perfected and made more efficient, and more early clinical trials are needed, both Butler and Yee say.
Five of the Dana-Farber patients went on to take ipilimumab, a human monoclonal antibody made by Bristol-Myers Squibb, which the U.S. Food and Drug Administration recently approved for treatment of metastatic melanoma. With the addition of ipilimumab, Butler says, tumors shrank in three of the five patients and stopped growing in the other two, a response far better than that shown in previous trials of the drug. Butler says this suggests his immunotherapy may help drugs work better.
“We’re very encouraged,” Butler says. “We’re also the first to admit that it could have something to do with patient selection or the small number of patients [in our study].” He says he’s in the process of putting together a clinical trial to look directly for any benefit from combined therapy.