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Moffitt tests vaccine using tumor cells
© St. Petersburg Times, TAMPA -- If it works, a vaccine made from Ron Wigginton's own cancer cells could be the ultimate designer drug and help prove an incredible concept: Just as the body can be taught to fight off tetanus or measles when inoculated, the body's immune system can be taught to recognize a certain cancer and kill it, or at least control it. Wigginton, a Tampa lawyer, has a form of non-Hodgkin's lymphoma, a common and incurable cancer of the lymph system that tends to kill slowly but surely. Now, he is one of about 560 people with the disease who will be enrolled over the next five years in one of the first large, advance-phase trials of a cancer vaccine. It is being conducted by the National Cancer Institute at several centers across the country, including H. Lee Moffitt Cancer Center in Tampa. If it works -- and results of a small pilot study were extremely promising -- the vaccine would be the first concrete validation of years of research into a string of cancer vaccines designed to encourage the body to take on the cancer that's killing it. One other vaccine, for melanoma, a deadly form of skin cancer, is now being tested. Trials for kidney and colon cancer vaccines are planned. The principle works like this: Patients' immune systems already have T-cells, which are supposed to keep in check foreign invaders like cancer or disease, explained Dr. Thomas P. Loughran Jr., the principal investigator of the lymphoma study at Moffitt. "Given this vaccine, they may be able to generate in the body specific T-cells that recognize the tumor as foreign. "This is unprecedented that we can do this now, and it's probably going to be important for other cancers and viruses, like HIV." Unlike the vaccines that ward off infectious diseases, from mumps to hepatitis, the lymphoma vaccine doesn't immunize someone against cancer. Rather, it is formulated for patients who already have the disease and whose cancer is in temporary remission after chemotherapy. But it works in much the same way: By mixing immune-boosting proteins with the cancer cells taken from the patient, then injecting it into the patient, the drug appears to alert the T-cells to the danger of the cancer cells, then prompts an immune response against them. In October, the NCI reported that in a pilot study of 20 patients with a certain form of non-Hodgkin's lymphoma, 18 were cancer-free after four years. Complete remission on the molecular level, impossible to achieve with chemotherapy, was achieved in 15. "It works indirectly, just like any other vaccine," said Dr. Larry W. Kwak, a senior investigator in the NCI's Center for Cancer Research, which has been developing this vaccine for 10 years. "It contains proteins from the tumor cell and activates the host immune system to make T-cells, which will then neutralize any cells that have that protein," he said. "Just like a tetanus shot contains part of the tetanus bacteria." There are several forms of non-Hodgkin's lymphoma, which affects about 41,000 Americans each year. The vaccine is being tested on the most common kind, called follicular non-Hodgkin's lymphoma, a slow-moving cancer that strikes up to about 25,000 people each year, usually ages 60 to 65. The cancer causes overproduction of the immune system's B-cells, white blood cells that produce disease-fighting antibodies. With B-cell lymphoma, a genetic mutation keeps the cells from dying naturally, so they accumulate in the blood and the lymph nodes. The cellular mutations develop over time, and may occur naturally or be prompted by exposure to certain toxins. Progression of this type of lymphoma, which Wigginton has, is generally slow but deadly, with an average survival time of seven to 10 years. Typically, chemotherapy will put it into remission, but tiny amounts of cancer cells survive in the bloodstream, and eventually they multiply. Three or four years later, the patient is sick again. It can usually be beaten again, and sometimes again. But each time it returns more quickly, and more aggressively. "You keep doing this over and over again until you get to your 10-year survival," Loughran said. "What they die of, basically, is a more aggressive lymphoma," or other diseases that take advantage of the weakened immune system. Wigginton, 66, who had always been in good health, was diagnosed in February 2000, after a large lump formed on his forehead. It didn't hurt, and he felt okay, so asked a plastic surgeon to remove it. The surgeon sent him to a dermatologist, who sent him to Moffitt. Although there is a one in three chance he will be given a placebo, rather than the vaccine, he decided to enroll in the NCI trial after learning the cancer could not be cured. "I'm not a passive-type person. I'm not inclined to say okay, it's not curable, let's just let it work its course," said Wigginton. He has a lot to live for: He has been married to his wife, Shirley, for 45 years and practices law with his son, Ron Jr. His daughter, Sheryl Whittaker, is an area art teacher. "I wanted to be more aggressive. The vaccine trial was the only thing I could do that was aggressive," he said. Everyone enrolled in the trial will visit NCI headquarters in Bethesda, Md., where a cancerous lymph node will be removed and milked for cancer cells. Those cells will be frozen and stored while the patient undergoes chemotherapy. In order to continue, the patient's cancer must go into remission. Wigginton went to NCI in the fall, and after several months of exhausting and sickening treatment, tests showed his cancer was in remission. NCI researchers now will mix his cancer cells with two immune-boosting proteins to make the vaccine, a process expected to last until November. He'll then start treatment with either the vaccine or the placebo, which will be concocted of simply the immune-boosting proteins. Not even his doctor will know which group he's in. If the cancer recurs during the trial, he must drop out, resume chemotherapy and hope for the best. "I'm just sitting here with my fingers crossed," Wigginton said. "At least, even if I get the placebo, I will have the comfort of knowing I pursued every avenue, including this one." Nationally, 70 people have enrolled in the study, which will follow each patient for five years. Moffitt hopes to recruit about 20 each year for the next five. Even if it appears successful, there are potential problems. Researchers won't truly know for years how well it works, or know whether the cancer can develop a resistance to the vaccine and proliferate despite it. Commercially making such a vaccine, which must be created from the cancer cells of each patient, also would require "a paradigm shift in the industry," Kwak said. But at least one biotech firm is interested, and researchers are looking for commonalities in cancer cells that may allow for a more standardized vaccine. "For the time being," Kwak said, "we're testing it really as a scientific proof of concept, and hope that the commercial viability will be there, if and when it's shown that it works." For informationH. Lee Moffitt Cancer Center in Tampa hopes to enroll 20 patients each year for the next five years for a National Cancer Institute clinical trial of a lymphoma vaccine. Nationally, the NCI hopes to enroll 563. To qualify, patients must be diagnosed with stage 3 or 4 slow-growing, follicular non-Hodgkin's lymphoma and have at least one enlarged and operable lymph node. They cannot have begun treatment with chemotherapy or other cancer-fighting agents. They can have had radiation therapy on individual lymph nodes. For information, patients or their doctors can contact the clinical research nurse in the hematology department at (813) 972-8391.
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