A novel approach to treating inoperable pancreatic cancer is under study at the Cancer Institute of New Jersey, using a vaccine injected directly into the tumor.
Research with mice has shown that when a vaccine is administered in the usual way, via a limb, no immune response is created. But when the vaccine is injected directly to the site of a cancerous tumor, the mice develop a system-wide immune response.
The Phase I clinical trial will study the safety of this approach in humans, said Edmund Lattime, one of the principal investigators and deputy director of the cancer institute. He is a professor of surgery there.
"We will take patients with locally advanced, inoperable pancreatic cancer," he said. "We will use an endoscope that will go into the stomach. It will image the tumor and take a biopsy of the tumor, and then we will inject the vaccine into the tumor itself."
Tackling a challenge
The vaccine to be used has already been tested for safety when injected into humans via an arm.
This trial is sponsored by the National Cancer Institute, which is providing the vaccine, known as PANVAC.
More than 42,500 Americans a year are diagnosed with pancreatic cancer, which has a five-year survival rate of 5 percent.
"There has not been a significant breakthrough in the treatment of pancreatic cancer since an upgrade in chemotherapy in the mid-1990s," said Elizabeth Poplin, a medical oncologist at the Cancer Institute of New Jersey and the study's lead researcher.
"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," she said.
Previous research has shown that the presence of a tumor in the body can actively inhibit the immune system from recognizing and destroying these same tumors.
Smaller dose, at first
The first three patients to be studied will receive smaller doses in their tumors than previously found safe when injected in the arm. If that proves to be safe, the next six patients will receive doses equal to those that have been previously tested through arm injections.
All of the patients will receive "booster shots" in their arms of a variant of the vaccine 24 hours after the tumor injections, Lattime said. Additional studies will observe if the tumor vaccine causes inflammation, he said.
The team hopes to be able to "compile enough data to bring us to the next level of research," said Tamir Ben-Menachem, a gastroenterologist who will perform the endoscopies.
Distributed by McClatchy-Tribune Information Services.