While most people probably think that cancer cells are foreign invaders, our bodies don’t see them that way. Cancers come from a person’s own tissues, so the body often does not recognize them as dangerous. That’s one reason creating cancer vaccines has been so difficult. And in fact, since the 1980s, doctors have been working to develop vaccines that teach the immune system to attack cancers, but for the most part they have failed. Over the past year, however, technology is being harnessed to develop a new generation of treatment vaccines – with some success.
Researchers led by Stephen Schuster, associate professor of medicine and director of lymphoma translational research at the University of Pennsylvania School of Medicine, have created a custom-made treatment vaccine – dubbed BiovaxID – that includes proteins from the patient’s own tumor. As they reported at the recent annual meeting of the American Society of Clinical Oncology (ASCO) in Orlando, they conducted a study in which the vaccine was shown to extend time to relapse by more than a year.
The physicians conducted the study on 117 patients with a slow-growing cancer of the lymph nodes called follicular lymphoma, which affects about 16,000 Americans each year, 90 percent of which will die within seven years of diagnosis. The patients selected for the study had gone into remission after standard chemotherapy. The doctors collected unique proteins from the patients’ tumors and coupled them with two other proteins designed to “stir up the immune system.” The goal was to create a vaccine that would target tumor cells only, not healthy ones. The researchers found that those patients who received the general immune boosters without the vaccine relapsed after 30 months, while those who received the vaccine and immune boosters relapsed after 44 months.
“The problem with this kind of lymphoma is that chemotherapy doesn’t actually cure anybody,” says ASCO president Dr. Richard Schilsky of the University of Chicago Medical Center, who was not involved in the study. “They all go into remission with chemotherapy but they all relapse,” Dr. Schilsky notes. “Each time you use chemotherapy, the remission lasts less time and eventually they just become refractory.” And adds, Barton Kamen, chief medical officer at the Leukemia and Lymphoma Society, “that’s why it’s important to get patients into remission and keep them in remission as long as possible.” Kamen notes that scientists will need to conduct larger studies to better understand how the vaccine works when combined with therapies that were not available when the study began a decade ago. While not “a home run,” it is a “remarkable initial step,” he says.
News Release: experimental vaccine delays relapse in some cancer patients www.usatoday.com May 31, 2009
News Release: Promising Results for Experimental Lymphoma Vaccine www.abcnews.go.com May 31, 2009
