There has recently been published a case study from an ongoing clinical study where an experimental immunotherapy treatment was tested. A patient, a 49-year-old woman with advanced breast cancer was told that she had only 3 months to live when she was included in the study. After several weeks of experimental treatment, her tumors disappeared. She has been in complete remission for already 22 months.
This treatment is a modified version of adoptive immunotherapy. Its technique implements harvesting patient’s immune cells – tumor-infiltrating lymphocytes. After been collected from the patient cancer-recognizing molecules are put onto tumor-infiltrating lymphocytes to make them able to find and destroy cancer cells. After that, the cells are transferred back into the patient’s body.
The results of this kind of immunotherapy have been inconsistent in early clinical trials as it showed high efficacy in some patients with certain types of cancers but much less effective in other cases. Especially this experimental treatment was not effective in common epithelial cancers probably due to the low level of mutations in these cancer cells.
This technique also includes sequencing the DNA and RNA from a patient’s tumor in order to find the specific mutations which are unique for this tumor as these mutations are the targets for lymphocytes. The tumor-infiltrating lymphocytes extracted from a patient are tested against thee particular mutations to detect lymphocytes which specifically identify and attack these mutations.
After the most effective lymphocytes are found they are then replicated to get a big number of them and infuse into the patient’s body. After the immune cells were infused back into the patient’s body in this trial the tumors began to disappear fairly fast. Judy Perkins, the patient in the study, recently has given the interview to the BBC, “About a week after [the therapy] I started to feel something, I had a tumor in my chest that I could feel shrinking. It took another week or two for it to completely go away.”
Steven Rosenberg, a leader of this ongoing clinical study, thinks this is a promising early result, indicating that this type of treatment can be applied to a wide variety of different kinds of cancers: “All cancers have mutations, and that’s what we’re attacking with this immunotherapy. It is ironic that the very mutations that cause cancer may prove to be the best targets to treat cancer.”