New immunotherapy uses patient's cells to attack tumors

Scientists have long been searching for a way to harness patients' immune systems to attack their own cancer, and researchers may have figured out just the way to do it.

The approach, outlined in the May 9 issue of Science, merges ideas from two hot fields in cancer drug development--immunotherapy and genetics--to target patient-specific mutations driving the growth of the cancer. In that sense, the therapy could hypothetically be tailored to any kind of cancer.

"The method we have developed provides a blueprint for using immunotherapy to specifically attack sporadic or driver mutations, unique to a patient's individual cancer," said Dr. Steven Rosenberg, chief of the surgery branch in National Cancer Institute's Center for Cancer Research, in a statement.

Immunotherapy has so far shown promise in more rare cancers, like melanoma and kidney cancers, but the conundrum in immunotherapy development has been how to treat more common epithelial cell cancers.

Previously, scientists did not know whether the human immune system was able to mount an effective response against mutant proteins produced by these epithelial cell cancers, or if such a response could even be used to develop a personalized immunotherapy. Epithelial cells line the body's internal and external surfaces, such as the skin, and are known to give rise to about 80% of common cancers, such as those in the digestive tract, lung, pancreas, bladder and other areas of the body.

Taking a type of immune cells called tumor-infiltrating lymphocytes, or TILs, from the patient, researchers used whole-exome sequencing to pick out those with the best antitumor activity--those that matched a mutation found in her cancer cell. They then grew a huge quantity of TIL cells in a lab that were found to react to the mutation and infused them into the patient.

After the TIL cells transfer, the patient's metastatic lung and liver tumors stabilized. After about 13 months, the patient's cancer progressed, and she was retreated with the therapy, in which 95% of the transferred cells were T cells specific to the cancer mutation. Six months after the second treatment, the patient's lung and liver tumors shrank.

- read the press release
- see the study abstract