From The National Geographic:
Two of 17 people with advanced melanoma—a deadly form of skin cancer—who underwent experimental treatment with the engineered immune cells saw their tumors shrivel. A year and a half after therapy began, the two patients were declared free of the disease. “This is the first example of an effective gene therapy that works in cancer patients,” said Steven Rosenberg, chief of surgery at the National Cancer Institute in Bethesda, Maryland, and leader of the research team.
The therapy has so far been applied only to melanoma patients. But the researchers are optimistic that their treatment can be used for many other types of cancer. The team has already engineered similar immune cells for more common tumors, such as breast, lung, and liver cancers.