There are already several cancer vaccine drugs nearing FDA approval. Dendreon's prostate cancer vaccine Provenge is awaiting the agency's OK, and Merck KGaA's Stimuvax is in trials for multiple myleoma, lung cancer, and breast cancer. But researchers hope that by making patients allergic to cancer early on, they can revolutionize the way the disease is treated.
UPMC researcher Olivera Finn is developing a vaccine to treat patients with advanced pancreatic cancer. While it's shown some success, Finn believes the treatment will work best in those who haven't yet developed the illness. So she's testing it on subjects who have precancerous polyps, hopoing that by administering the treatment early, disease progression can be halted. The idea is to make the body allergic to antigents, markers found on the surface of cancer cells. "If we immunize early on, the cells that become abnormal might actually be eliminated by a strong immune response," says Finn. That immune response is most likely to work early in a disease, when the body's immune system is still strong. Finn is several years away from reporting results.
In a different study being conducted by UPMC neurosurgeon Hideho Okada, researchers will test whether the immune system booster Hiltonol can slow or stop gliomas, a type of brain cancer. "Our goal is to educate the immune system so that it recognizes the cancer-specific antigens," says Okada. Hiltonol, made by Seattle's Oncovir, is being tested in 12 cancer vaccine trials. It sends a warning signal to the patient's immune system telling it to attack the cancer.
Part of the challenge of testing preventative vaccines in people with early-stage cancer is time; patients would have to be followed for years for researchers to determine if early treatment was effective. And that's enormously expensive. "...[I]t's much easier to do that after you've got a revenue-generating product," says Robert Kirkman, president of Oncothyreon, which originally developed Stimuvax. That's why developers choose to treat late-stage diseases first.
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