CINJ researchers develop new vaccine strategy for pancreatic cancer

Feb 11 2010

More than 42,500 people in the United States were diagnosed with pancreatic cancer last year and nearly 35,200 died from the disease, according to The American Cancer Society. The lifetime risk of developing pancreatic cancer is about one in 76 for both men and women and there is a five-year survival rate of only five percent, despite advancements in surgery, chemotherapy and radiation treatment.

That is why researchers at The Cancer Institute of New Jersey (CINJ) are investigating the development of a series of vaccine injections to see if they will produce an immune response against pancreatic cancer. CINJ is a Center of Excellence of UMDNJ-Robert Wood Johnson Medical School.

It has been known for a number of years based on studies by scientists at CINJ and elsewhere, that the presence of a tumor in the body can actively inhibit the immune system from recognizing and destroying these same tumors. Studies on mouse models at CINJ have shown this blockade of immunity also prevents traditional cancer vaccines from producing a good response.

As part of these studies at CINJ, investigators have shown that injecting a vaccine and other immunity-producing drugs into the tumor itself -- rather than the traditional site of the skin -- can result in a reversal of the immune blockade and the development of specific immunity to the tumor. This body-wide tumor-specific immunity has the potential of inhibiting the growth of the original tumor as well as eliminating small deposits of tumor that can form metastases.

These findings have led to the development of a vaccine strategy targeting patients with pancreatic cancer, where the vaccine would be injected directly into the tumor. It is believed that this trial would be the first such study to evaluate direct injection into a pancreas tumor to enhance the body's immune response to help fight the cancer.

Elizabeth Poplin, MD, medical oncologist at CINJ and professor of medicine at UMDNJ-Robert Wood Johnson Medical School, is the lead researcher on this clinical trial sponsored by the National Cancer Institute, which will look at the investigational vaccine known as PANVAC. PANVAC has special genes added to it that might stimulate a person's immune system to recognize and develop an immune response to the disease.

"There has not been a significant breakthrough in the treatment of pancreatic cancer since an upgrade in chemotherapy in the mid 1990s," said Dr. Poplin. "When you talk about a disease that on average carries only a five-percent survival rate, the possibility of identifying better treatment and management options, especially by potentially utilizing the body's own defenses, has become a challenge that my colleagues and I are committed to tackling."

Two types of PANVAC will be utilized in the two-year study, which will test approximately a dozen patients whose pancreatic cancer cannot be removed through surgery. PANVAC-V, which uses the same virus as the smallpox vaccine, is a live but weakened vaccinia vaccine (meaning the virus can still multiply) that will be given in the arm. PANVAC-F (a live Fowlpox virus that cannot multiply) would be injected into the arm and into the tumor itself. Direct tumor injection would take place through a procedure known as endoscopic ultrasound, in which a scope is inserted through the mouth and into the stomach. From inside the stomach, the pancreas can be seen clearly, allowing injection of the vaccine into the tumor.

Tamir Ben-Menachem, MD, gastroenterologist at CINJ; director of endoscopy and associate professor of medicine at UMDNJ-Robert Wood Johnson Medical School, is an investigator on the research team who will perform the endoscopies. "Traditionally, vaccination treatment is always administered away from the affected site. In recent years, technology has advanced far enough to allow us to explore the option of injecting the tumor directly," said Dr. Ben-Menachem. "It is my hope and that of the investigative team here at CINJ that we will be able to compile enough data to bring us to the next level of research. It is only through such study that we will be able to learn more about the process and improve the treatment of pancreatic cancer."

Patients with pancreatic cancer that is either localized to the pancreas but cannot be removed by surgery, or has minimally spread beyond the pancreas, are eligible to take part in the study, although other criteria must be met. For more information on how to take part, individuals should call CINJ's Office of Human Research Services at 732-235-8675.

Clinical trials, often called cancer research studies, test new treatments and new ways of using existing treatments for cancer. At CINJ, researchers use these studies to answer questions about how a treatment affects the human body and to make sure it is safe and effective. There are several types of clinical trials that are currently underway at CINJ, including those that diagnose, treat, prevent, and manage symptoms of cancer. Many treatments used today, whether it is drugs or vaccines; ways to do surgery or give radiation therapy; or combinations of treatments, are the results of past clinical trials.

As New Jersey's only National Cancer Institute-designated Comprehensive Cancer Center, CINJ offers patients access to treatment options not available at other institutions within the state. CINJ currently enrolls more than 1,000 patients on clinical trials, including approximately 15 percent of all new adult cancer patients and approximately 70 percent of all pediatric cancer patients. Enrollment in these studies nationwide is fewer than five percent of all adult cancer patients.