Researchers trained white blood cells to attack tumors tend to fade away quickly when injected into cancer patients.
Dana-Farber Cancer Institute scientists, however, have developed a technique that can cause such cells to survive in patients’ bloodstreams for well over a year, in some cases, without the need of other, highly toxic treatments, a new study shows.
In a paper published in the Apr. 27 issue of Science Translational Medicine, the researchers report the results of a small, Phase I study in which the technique — a form of “adoptive immunotherapy” — was tested in nine patients with advanced melanoma.
Ten weeks after starting the therapy, seven of the nine patients had more of the specially trained, tumor-hunting cells than they had started with. Three of the patients had stable disease — neither advancing nor retreating — and one had shrinkage of a tumor that had spread to the lung. Another patient experienced a complete remission, with no tumors visible on CT or PET scans. Today, 25 months after receiving the one-time therapy, he has no evidence of cancer.
The results represent the longest that the injected cells — known as anti-tumor T cells — have ever endured in cancer patients without the use of supplemental treatments — treatments that, while effective, often have harsh side effects.
“The study demonstrates it is possible to maintain high levels of anti-tumor T cells in patients over a long period of time while avoiding the complications of conventional approaches,” says the study’s lead author, Marcus Butler, MD, of Dana-Farber’s Early Drug Development Center. “Our technique opens the way to therapies that produce less-toxic, long-lasting immune system attacks on cancer cells.”
Melanoma skin cancers were diagnosed in more than 68,000 Americans in 2010, according to the American Cancer Society, and the numbers have been rising for more than 30 years. If detected and removed at an early stage, melanomas can usually be cured, but once the disease has spread to distant sites, the median survival time for patients is less than a year. Scientists are developing an array of novel treatment approaches to improve those odds.
Source: Dana-Farber Cancer Institute, USA