Comparing the Effectiveness of Vaccine Therapy With or Without Additional Immunotherapy
Can a drug that helps the immune system attack tumors also help make a combination of pancreatic cancer vaccines more effective against metastatic cancer?
That question is being explored in a clinical trial that compares treatment with and without two types of immunotherapy.
Immunotherapy is used in cancer treatment to stimulate the immune system. Vaccines, a type of immunotherapy, can boost the immune response to a tumor. Earlier trials have found that using just one type of immunotherapy in a treatment has not been effective in fighting pancreatic cancer. Researchers are now trying combinations of immune-based therapies.
Two Cancer Vaccines
In one clinical trial, all patients receive the combination of cyclophosphamide/GVAX pancreas vaccine and CRS-207 vaccine. Cyclophosphamide is a chemotherapy drug that interferes with DNA replication so the tumor cannot grow. The drug, given at a low dose, targets cells that regulate the immune system function, in this case the ones that suppress immune function. The GVAX and CRS-207 vaccines each stimulate different aspects of the immune system to kill the tumor cells.
Adding Another Type of Immunotherapy
Some patients receive the cyclophosphamide/vaccine combination plus another type of immunotherapy, one that uses a monoclonal antibody. Cancer cells multiply in part by evading the immune system; the monoclonal antibody in this trial is an immune checkpoint blockade drug. It works by blocking a chemical that helps tumors evade the immune system. The monoclonal antibody plus the two vaccines add another type of immune system response to the cancer treatment. This approach of taking the “brakes” off the immune system has shown some promise as an effective treatment in other cancers, such as melanoma and lung cancer.
We encourage you to consult your physicians for clinical trials that may be right for you. The website ClinicalTrials.gov provides more details about this trial as well as many others. You can visit the EmergingMed Trial Finder for a listing of all active pancreatic cancer clinical trials.
This trial is now complete. To learn more about immunotherapy and cancer vaccines, read the story “Putting the Immune System on the Offensive.”