In a recent study from a team of Johns Hopkins investigators, the GVAX vaccine was combined with an immune modulator drug called cyclophosphamide, which targets a type of immune cell, called Tregs, that typically suppresses the immune response of certain T cells that destroy cancer. This "reprogramming" was meant to make the tumors vulnerable to immune-based therapies.The vaccine combination was tested in 39 people with pancreatic ductal adenocarcinoma (PDAC), which is the most common form of pancreatic cancer. Fewer than 5% of patients with the disease survive 5 years after diagnosis, and patients often become resistant to standard chemotherapy. Although PDACs usually don't trigger an immune response against the cancer cells their comprise, this vaccine, which was developed by researcher Elizabeth Jaffee, MD, could potentially convert many types of tumors, including PDAC, to a state where immunotherapies can be more effective.
The researchers are planning another study in which patients with PDAC will be tested with a combination of GVAX and an antibody to PD-1, one of the immune-suppressing molecules that became more active after vaccination. The authors of this study, published in the June 18 issue of Cancer Immunology Research, suspect that combinations of immune therapies will have the most significant effect.
Researchers at the Johns Hopkins Kimmel Cancer Center have developed and tested a vaccine that triggered the growth of immune cell nodules within pancreatic tumors, essentially reprogramming these intractable cancers and potentially making them vulnerable to immune-based therapies.