The hottest topic at April’s meeting of the American Association of Cancer Research was the immunotherapy of cancer. Over 18,000 cancer specialists at this meeting were excited at the thought of unleashing your body’s own immune response to combat cancer. At the same time, the results of two key studies were published in the prestigious New England Journal of Medicine, the April 19 2015 edition. These results support the latest advances in immunotherapy.
Immune Check Point Inhibitors Are Effective for Patients with Advanced Lung Cancer
1. Even when chemotherapy fails, immunotherapy of cancer with immune check point inhibitors takes advantage of the fact that many cancers can evade the body’s own immune response from activated T-cells. These T-cells can kill cancer, but the newly approved drug, Ipilimumab, takes the natural brakes off the immune system. Unleashing it’s power.
Dr. Edward Garon and colleagues of the KeyNote-001 investigation group, studied 495 patients with advanced lung cancer, many of whom had prior treatment with chemotherapy. The exciting finding was that 18% of 394 previously treated patients and 24.8 % of 101 previously untreated patients, had a positive response to the newly approved immune checkpoint inhibitor drug. The drug, Ipilimumab, works by blocking the CTLA-4 molecule on activated T-cells. Of the advanced lung cancer patients who responded to the newly approved drug, 84% had no lung cancer progression. Importantly, the median or average response lasted for over 12 months. Therefore, this new drug extending the life of these lung cancer patients without giving them more chemotherapy.
A Combination of 2 Different Immune Check Point Inhibitors Are More Effective Than One for Patients with Metastatic Melanoma
2. Dr. Caroline Robert and coworkers of the KeyNote-006 investigation group conducted a randomized, controlled phase 3 trial on 834 patients with advanced malignant melanoma. This type of clinical trial is the gold standard of clinical trials. The study showed conclusively that the immune check point inhibitors Pembrolizumab plus Ipilimumab were better than Ipilimumab alone. The relative risk of cancer progression or death was decreased by 42% with the combination regimen. And with a low risk of harmful side effects – less than 10% of patients.
Adding Stereotactic Body Radiotherapy May Be the Most Effective Treatment Combination
3. One reason that patients with metastatic melanoma may not respond to Ipilimumab is that their immune system has not been activated against their own cancer. Stereotactic body radiotherapy, like that delivered by CyberKnife, has been shown to release tumor antigens. Tumor antigens are the molecules on the surface of cancer cells that are recognized as foreign by the body’s immune system (just like a cold virus). These tumor antigens can stimulate the body’s own immune system to activate T cells- the immune cells that can kill cancer- creating, if you will, a “personalized cancer vaccine.” A multi-disciplinary team of cancer specialists at the University of Pennsylvania School of Medicine is currently conducting a trial that combines stereotactic body radiotherapy with Ipilimumab. And the preliminary results are very optimistic.
I believe that the new wave of the future for many cancers will be upfront CyberKnife treatment followed by immune check point inhibitors. Surgery and/or chemotherapy will follow, but only after the patient’s own immune system has been ignited.
Please feel free to contact me, Edward Hughes, M.D. PhD, at First Dayton CyberKnife 1-866-DAYTON1 if you have questions about immunotherapy and CyberKnife.