WHY A VACCINE? Vaccine trials are nothing new in the search for effective cancer treatments. The idea is to "jump-start" the immune system into recognizing and fighting cancer cells.
Traditionally, vaccines have been used only as last resorts when chemotherapy and other treatments have failed. By then, the patient might be so weakened that the chances for recovery are slim. A new vaccine directed specifically at colorectal cancer is showing promise. Unlike its predecessors, this vaccine is being administered immediately upon diagnosis along with chemotherapy.
HOW DOES IT WORK? The vaccine, called ALVAC-CEA/B7.1, is a deactivated strain of a virus. Researchers are interested in this virus because of the antigens it displays. They are identical to the antigens exhibited by colorectal tumors. The body's immune system should normally fight cells displaying these antigens, but many people with colorectal cancer have immune systems that don't recognize cells as bad and therefore, don't fight them. The idea behind the vaccine is to introduce even more of the tumor-associated antigens (TAA) into the body so the immune system becomes "awakened" or "trained" to attack the cancer cells.
When a patient qualifies for the experimental protocol, the patient begins the therapy immediately and in conjunction with traditional chemotherapy. The vaccine is administered at weekly intervals through subcutaneous injection, meaning just under the skin, as opposed to being injected into a muscle of the vein. Although the studies are currently in early stages, it appears that patients are tolerating the joint vaccine/chemotherapy regimen without any unusual side effects.
HOW CAN I PARTICIPATE? Laboratory studies have suggested that the vaccine does, in fact, activate immune responses. However, it is still unclear just how effective the vaccine will be in defeating colorectal cancer. For this reason, studies are ongoing, and researchers are seeking qualified candidates for participation.
Patients must have metastatic colorectal cancer and must not have received chemotherapy. Medical centers participating in the trial are located in Los Angeles (USC/Norris Cancer Center) as well as New York, Washington, D.C., Philadelphia, Birmingham, Chicago, and Ontario, Canada.
COST: For the purposes of the clinical trials, the vaccine's costs are covered by the pharmaceutical company that created it. A patient's health insurance is expected to cover the costs associated with chemotherapy, x-rays, and other tests.
FOR MORE INFORMATION, PLEASE CONTACT:
Heinz-Josef Lenz, M.D.
University of Southern California
1441 Eastlake Avenue, Suite 3456
Los Angeles, CA 90089-9173