Combining Two Vaccines Benefits Patients with Metastatic Pancreatic Cancer

Gastrointestinal Cancers Symposium
January 14, 2014

Researchers have found that treatment with two different vaccines, GVAX Pancreas followed by CRS-207, helps people with metastatic pancreatic ductal adenocarcinoma (PDAC) live longer. PDAC is the most common type of pancreatic cancer. This study shows that immunotherapy (treatment designed to boost the body's natural defenses to fight the cancer) can help treat pancreatic cancer and appears to cause less serious side effects than chemotherapy.

The GVAX vaccine is made up of pancreatic cancer cells that scientists have changed so they produce a protein that stimulates the immune system. GVAX is given with a low dose of a common cancer drug called cyclophosphamide (Cytoxan) to make it work better. The second vaccine, CRS-207, contains a weakened form of a bacterium that has been modified in a laboratory to cause the immune system to recognize a specific protein found at high levels on pancreatic cancer cells. Essentially, this combined vaccination approach enhances a person’s natural immune system and trains it to recognize and attack pancreatic tumors.

As part of this study, 90 patients with metastatic PDAC were either given the GVAX vaccine followed by CRS-207 or GVAX alone. The researchers found that half of the patients who received the two-vaccine therapy were alive after six months compared with about four months for those who received only GVAX. About 24% of patients who received combination vaccine treatment were still alive after one year compared with 12% of those who received GVAX alone. The vaccine combination was even more effective when the person received two doses of GVAX and at least one dose of CRS-207 and when the person had received two or more different treatments before starting vaccine therapy.

What this means for patients

“We’re excited that patients with metastatic pancreatic cancer may soon have an alternative to chemotherapy that could come with fewer side effects,” said lead study author Dung T. Le, MD, an assistant professor of medicine at the Johns Hopkins University Sidney Kimmel Comprehensive Cancer Center in Baltimore, Maryland and a 2008 Conquer Cancer Foundation of ASCO Career Development Award recipient. “This study is just a first step, and we believe we’ll be able to take this approach further.”

The GVAX/CRS-207 combination is one of several related immunotherapies currently being investigated in clinical trials. The researchers who conducted this study are about to open a larger clinical trial that will compare the benefits of the GVAX/CRS-207 vaccine combination, CRS-207 alone, and chemotherapy. They are also looking at combining GVAX with other immunotherapies. If you are interested in participating in a clinical trial, talk with your doctor for more information. 

Questions to ask the doctor

  • What stage of pancreatic cancer do I have? What does this mean?
  • What are my treatment options?
  • What clinical trials are open to me?

For More Information

Guide to Pancreatic Cancer

Understanding Cancer Vaccines

Understanding Immunotherapy

When the First Treatment Doesn’t Work