The results show how natural tumor infiltrating lymphocytes (TIL) were extracted from a patient's tumor, grown outside the body to increase their number, and injected back into the patient to fight cancer. The patient had previously received several forms of treatment, including hormone therapy and chemotherapy, but none of them stopped the progression of the cancer. After the treatment, all of the patient's tumors disappeared, and after 22 months she is still in remission.
colorectal, bile ducts and cervix.
Although the results are undoubtedly promising, especially because of the low level of toxicity experienced by patients compared to chemotherapy, cancer often develops resistance to treatment, and often metastases can have mutations different from the original tumor.
Is it so easy for patients to develop resistance to TIL?
“Ironically, the very mutations that caused cancer could be the Achilles' heel that can kill cancer. It is very important to target multiple mutations at once,”Rosenberg said.
Ironically, this is one of the advantages of many older chemotherapy drugs over newer, personalized treatments. Because chemotherapy indiscriminately permeates the genome with carpet-bombing damage, it becomes more difficult for a cancer cell to develop resistance to it. Choosing TILs that target a small number of mutated proteins in the tumor may increase the likelihood that cancer will develop resistance. More work is needed in this area, as well as techniques for studying which mutations in cancer cells are possible targets of TIL.
If major work confirms these excellent preliminary results, developing personalized patient therapy is undoubtedly a financial and technical challenge that requires specialized laboratories and expertise. How practical is it to deliver fully personalized therapy?
And several companies are already testing TIL treatments, including Bristol-Myers Squibb and Iovance Biotherapeutics, the latter of which specifically focuses on TIL. Clinical trials of TIL are currently underway for melanoma, cervical cancer, lung cancer, and even the notoriously difficult-to-treat glioblastoma and pancreatic cancer.
It's not often that entirely new cancer treatments come into the fray with impressive results such as those shown by TIL in these examples. What is urgently needed now is the results of larger clinical trials and ongoing monitoring of patients who have been successfully treated to make sure they are not having problems.
Promotional video:
“This is an illustrative example that once again shows us the power of immunotherapy,” said Tom Misteli, PhD, head of CCR at the NCI. "If confirmed on a larger scale, it promises to further expand the scope of this T-cell therapy to a broader spectrum of cancers."