Immunotherapy is the groundbreaking use of drugs, therapeutic vaccines, viruses, antibodies, and cell-based techniques to activate the body’s own immune system to identify and destroy or slow the growth of certain kinds of cancer cells.
Some patients with prostate, bladder, melanoma, and kidney cancers are being treated with these techniques today. Fox Chase clinical researchers are currently investigating a variety of immunotherapy approaches to determine which patients might benefit from treatment for colorectal carcinoma, non-small cell lung cancer, metastatic breast cancer, advanced solid tumors, muscle invasive bladder cancer, prostate cancer, and melanoma.
We are in the earliest stages of understanding how to unleash, activate or educate the immune system to destroy cancer but the evidence so far is very promising. On the pro side, responses may be durable for month or years, side effects are different from traditional chemotherapy and are often reversible, and resistance to the drugs may be minimized. On the other side, though, the majority of patients do not benefit from current immunotherapy treatments, severe side effects are possible though not common, and no biomarkers have been discovered to help identify who will benefit from these approaches.
As we learn and understand more about how cancer takes hold, grows and responds to innovative treatments, innovative immunotherapy approaches are being developed that can work alone or in conjunction with chemotherapy and radiation to more effectively treat this devastating disease.
How immunotherapy works
The immune system naturally scans the body for cancers and is usually effective in killing cancerous cells. However, sometimes a tumor finds ways to avoid immune cells, allowing it to grow and spread, undisturbed by the immune response. If the immune system can be trained or re-focused to recognize and attack a cancer, it can adapt along with the cancer and maintain a longer-term response. That’s what immunotherapy does.
Until very recently, there were only two approaches to treating metastasized cancer (cancer which has spread beyond the original tumor site). Chemotherapy is a system-wide treatment with medications that kill cancer cells but can also destroy normal cells. Side effects can also be severe. Chemotherapy use is limited because the body can only tolerate a certain level of toxicity from the drugs and cancers usually evolve and become resistant to treatment over time. The second generation of treatments is called targeted therapy, in which medications destroy specific cancer cells, with little to no effect on normal cells.
While the recent focus on immunotherapy dates back to the late 1980s, the first discovery goes back to 1891, when physician William B. Coley saw that metastatic bone tumors disappeared in a small percentage of patients who got a particular streptococcus infection, indicating that the immune system was jumpstarted to target cancer that had spread. Since then, a number of cancers have responded to treatment, though not in every patient and not without considerable side effects.
Today, Fox Chase is committed to the clinical development of immunotherapy. Our researchers will help discover which patients have the “markers” to benefit from treatment, how immunotherapy can be combined with chemotherapy, targeted therapy, and radiation for more effective cancer eradication, and whether the approaches can be used not only to treat cancer after it has spread, but also to prevent cancer recurrence.