New immune therapy drugs for cancer include a new class of drugs that could change the way doctors and patients fight the disease. Three major pharmaceutical companies that are developing these drugs shared data from their studies at a meeting of American Society of Clinical Oncology. The new immune therapy drugs for cancer could potentially be on the market by early 2015.
The new drugs, which are still being tested, work by stimulating the immune system to attack cancer cells similar to how it attacks bacteria. This could provide an alternative to chemotherapy, which is not well tolerated by many patients.
These new cancer medications are a type of immunotherapy that works by disabling a brake on the immune system called the programmed death 1 receptor, or PD-1. The PD-1 drugs are known to shrink tumors in 15% to 50% of patients.
Signs point to longer lifespan as well with treatment with PD-1 drugs. In cases of metastatic cancer, a successful drug can slow a patient’s rate of decline, but eventually the cancer kills all patients. However, with new immune therapy drugs for cancer like the British drug Yervoy for melanoma—which uses a different immune system brake than the PD-1 drugs—a certain percentage of patients do not die of the disease, or at least they live much longer than with other treatments. Experts hope that this extended life will be an effect of the PD-1 drugs as well.
Benefits of using the immune system to fight cancer are:
- It can be used for many types of cancer
- It may produce longer remissions than chemotherapy
- It is more natural and holistic
- It does not involve putting chemicals and poison into the body
- The immune system can adapt to rapidly mutating cells, so the cancer does not become resistant to the treatment
While the new PD-1 drugs seem to be tolerated well, there are some cautions regarding stimulating the immune system. Autoimmune diseases can cause the body to attack healthy cells. Some patients taking PD-1 drugs have experienced lung inflammation.
Immunotherapy and prostate cancer
One of the latest prostate cancer treatments using immunotherapy is Provenge (sipuleucel-T). Provenge is a therapy for late-stage metastatic prostate cancer that is resistant to hormone therapy. It was approved by the FDA in April of 2010. Provenge works similar to a vaccine. Each dose of Provenge involves collecting a patient’s blood, harvesting certain cells, and then returning the remaining blood to the patient. The harvested cells are modified, or trained, to attack the cancer cells and then given back to the patient a few days later via an infusion.
Patients taking Provenge are using their bodies’ own cells to help them fight prostate cancer. In clinical trials, men who took Provenge lived an average of 25.8 months compared with men who took a placebo, who lived on average 21.7 months. On average, Provenge extended life 4.1 months longer than the placebo.
Provenge differs from the new PD-1 drugs in that Provenge trains the body to attack the cancer, while the new drugs tackle the problem of immune system suppression. With these new immune therapy drugs for cancer, the world’s top cancer specialists feel that we are approaching an important milestone in attacking this disease.
Read more in our Prostate Cancer Health Center.
Pollack A. Cancer drugs empower the body’s own defense system. The New York Times. June 3, 2013.