Immunotherapy and Mesothelioma
The immune system is your body’s natural defense against disease including cancer.
Immunotherapy is a type of cancer treatment that uses your immune system to help fight or control cancer. Many cancers, including mesothelioma, are able to hide from your immune system so some immunotherapies are designed to make it is easier for the immune system to find them. Other immunotherapies boost your immune system to work better against cancer. Today, millions of dollars are spent by pharmaceutical companies to develop immunotherapies against mesothelioma and other cancers, but independent doctors and clinics have been interested in this approach for at least 50 years.
Josef M. Issels was born 1907. He was a German physician known for promoting an alternative cancer therapy regimen, the Issels treatment. He believed that cancer was caused by the weakening of the immune system and his treatment was designed to use the body’s immune system to help fight cancer. The Issels treatment is currently considered unproven.
Lawrence Burton was born in New York in 1926. He earned a Ph.D. in Experimental Zoology from NYU. Working with a team of cancer researchers, he discovered a tumor inhibiting factor that reduces cancer in mice with leukemia. Dr. Burton discovered that these “blood fractions” were missing in cancer patients. When he supplemented these fractions, they helped to control the growth of cancer. Dr. Burton never claimed that his approach, which is a type of immunotherapy, was a cure. He described it as an “insulin” for cancer. The Burton therapy is not FDA approved.
Keytruda is one of a number of immunotherapies currently being tested in mesothelioma.
Here's How It Works
The immune system sends cells called T cells throughout your body to find and fight infections and diseases such as cancer. Cancer cells like mesothelioma cells may use the PD-1 pathway to hide from T cells.
The PD‑1 pathway acts as a type of “off switch” that helps keep the T cells from attacking other cells in the body. When cancer cells trigger this switch, the T cells can’t attack them and the mesothelioma can grow and spread. Keytruda is a type of immunotherapy that works by blocking the PD-1 pathway and to help prevent cancer cells from hiding from the immune system.
In a European clinical trial of Keytruda on mesothelioma patients the results were:
- 93 patients (48 from Switzerland and 45 from Australia) with mesothelioma were treated
- 68 patients (73%) had epithelioid mesothelioma
- 48 of the 93 patients already had undergone a previous treatment
- 18% of patients had their tumors reduce in size
- The patients went for a median of 3.1 months before their tumors started growing
- The median survival was 7.2 months
- For patients who had only one previous treatment (i.e. chemo), the median overall survival was 10.2 months