Research from The Cancer Institute of New Jersey (CINJ) shows that a series of vaccine injections given directly into a pancreatic cancer tumor is shown to be associated with stable disease in patients who are not candidates for surgery. Early results of a clinical trial being conducted at CINJ are being presented as a "highly-rated poster" at the Annual Meeting of the American Association for Cancer Research (AACR) being held in Chicago this week. CINJ is a Center of Excellence of the University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School.
Previous laboratory research by CINJ investigators has shown that injecting a vaccine and other immunity-producing drugs directly into a cancer tumor -- as opposed to the normal injection site of the skin -- can result in a reversal of the traditional immune blockade and the development of specific immunity to the tumor throughout the body. This tumor-specific immunity has the potential of blocking the growth of the original tumor as well as eliminating small tumor deposits that can cause the cancer to spread. Stemming from this research is a clinical trial that is the focus of this abstract. The study by CINJ investigators further tests this vaccine strategy, designed to heighten the role of the body's own immune system in fighting cancer.
The investigational vaccine known as PANVAC contains gene additives that might stimulate a person's immune system to recognize and develop an immune response to the disease. Two types of PANVAC have been utilized in this trial. 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 is given in the arm. PANVAC-F (a live Fowlpox virus that cannot multiply) is injected into the tumor itself and subsequently into the arm as a boost. Direct tumor injection takes place during a procedure known as endoscopic ultrasound, in which a scope is inserted through the mouth and into the stomach so that the tumor in the pancreas can be seen.
During the first phase of the study, which looked at six participants whose cancer could not be removed through surgery, patients were evaluated for toxicity, tumor progression and the presence of tumor markers for pancreatic cancer. One patient was treated with gemcitabine, followed by capecitabine and radiation, prior to the vaccination regimen and received no other treatment after. Two patients were removed from the study after two weeks due to rapid disease progression; one died six months after first being placed on the trial and the other after one month. Of the remaining four patients, three received gemcitabine - a standard treatment for pancreatic cancer - after receiving vaccination treatment.
Of these four patients, all were shown to have clinically stable disease after 24 months, 22 months, 21 months and 18 months respectively. The second part of the trial is still accruing additional participants, who are being given a higher dosage of PANVAC-F during direct injection of the tumor.
CINJ Deputy Director Edmund Lattime, PhD, is the senior researcher on the study, which is sponsored by the National Cancer Institute (NCI). "We're seeing results of clinically stable disease for a year and a half now in some cases with this treatment regimen. Considering pancreatic cancer only carries a five-year, five percent survival rate, these findings are very encouraging and will hopefully lead to more effective ways of managing and treating this disease," noted Dr. Lattime who is also a professor of surgery and a professor of molecular genetics, microbiology and immunology at UMDNJ-Robert Wood Johnson Medical School.
Along with Lattime, authors include Elizabeth Poplin, David August, Tamir Ben-Menachem, Hazar Michael and Renee Artymyshyn of CINJ and UMDNJ-Robert Wood Johnson Medical School; James L. Gulley and Jeffrey Schlom of the NCI; and Robert S. DiPaola of CINJ and UMDNJ-Robert Wood Johnson Medical School.
The work was supported by the NCI Cancer Therapeutics Evaluation Program and by NCI U01-CA07031 and P30-CA72720. This research also was presented at the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics meeting held in San Francisco this past November.
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