After decades of painstaking research, a number of recent clinical trials have shown that the patient’s own immune system can be used to attack cancer cells. In the January 22nd issue of the New England Journal of Medicine, two separate reports provide even more data on the emerging role of immune therapy in the treatment of metastatic cancer. Immunotherapy for cancer has now focused on the class of drugs called immune checkpoint inhibitors. These drugs are actually antibodies themselves, and inhibit the body’s own natural brakes on the immune system.
The first article described better survival for patients with metastatic melanoma, the deadliest form of skin cancer, who received the drug nivolumab. Results of this study strongly support the approval of nivolumab as first-line treatment for many patients with metastatic melanoma. The second article showed a very high response rate of 87% to nivolumab for patients with Hodgkin’s lymphoma in whom chemotherapy failed.
Dr. Drew Pardoll, M.D. PhD, co-director of the Johns Hopkins immunology program, stated that “I divide pharmaceutical companies into two categories. They’re in immunotherapy up to their eye balls or they want to be.” This is an exciting time in medical research. We are just beginning to understand how powerful our own immune system can be with the right help.
Another class of drugs focuses on inhibiting immune cell molecule called CTLA-4. There are now at least 3 examples of successful immune mediated tumor rejection after treatment with radiation therapy and CTLA-4 checkpoint blockade. Importantly, each of these studies used short course/high dose radiation therapy combined with the CTLA-4 antibody. Two studies again focused on metastatic melanoma, and another one focused on metastatic lung cancer. I believe that we are just at the dawn of integrating short course/high dose radiation therapy, such as that delivered by the CyberKnife, with immunotherapy. In the coming decade, there will continue to be exciting advances with these new modalities to improve patient’s quality of life.
It now looks like the time and money spent in tumor immunology is paying real dividends for patients. The hope is that the immune checkpoint drugs can be combined with traditional forms of cancer therapy, like surgery and radiation therapy, to treat even more cancers. Stay tuned.