The vaccine stimulates the body to attack tumor cells of advanced breast and ovarian cancer patients, improving their overall survival times and stopping the disease for a few of the breast cancer patients.
In the study, the PANVAC vaccine, as it is called, helped the body’s immune system recognize proteins produced specifically by cancer cells, reported Dr. James Gulley, Director and Deputy Chief of the Clinical Trials Group at the Laboratory of Tumor Immunology and Biology at the U.S. National Cancer Institute and author of the study.
All of the 26 women that received the vaccine in the study had breast or ovarian cancer that had spread to other organs and were considered “heavily pre-treated” with other therapies, with 21 having received at least three chemotherapy regimens. In addition to the four breast cancer patients whose disease stopped progressing, one woman with breast cancer experienced a “complete response,” meaning her cancer disappeared.
“Most participants — whose average age was 57 — had exhausted other forms of treatment, ” Dr.Gulley commented, “Which likely hampered their immune systems from responding as fully to the vaccine as they otherwise might have.” As therapeutic vaccines become more established, Dr. Gulley feels they might prove even more effective in patients whose disease is less advanced.
Among the 12 study participants with breast cancer, the median time before the disease continued to progress was 2.5 months and the median overall survival was 13.7 months. For the 14 patients with ovarian cancer, the median time to progression was two months and the median overall survival was 15 months.
Side effects from the vaccine were exceedingly mild, with minor injection-site reactions the most common problem reported.
To learn more, go to the U.S. National Cancer Institute information on cancer vaccines.
SOURCE: James L. Gulley, M.D., Ph.D., director, clinical trials group, deputy chief, Laboratory of Tumor Immunology and Biology, U.S. National Cancer Institute, Bethesda, Md.