The three vaccines with recent success don't work in all patients either, even though researchers tried to define patient populations that would be most amenable to vaccine therapy. In the melanoma vaccine trial, only patients with certain tissue types -- akin to tissue-typing for organ transplantation -- were included.
In the lymphoma vaccine trial, only patients who responded to chemotherapy and remained in remission for six months were eligible to receive the vaccine.
For The Record
Los Angeles Times Wednesday, July 08, 2009 Home Edition Main News Part A Page 4 National Desk 1 inches; 46 words Type of Material: Correction
Cancer vaccines: An article in Monday's Health section about vaccines used to fight cancer stated that the vaccine BiovaxID delayed remission of lymphoma in patients after chemotherapy by more than one year, on average. BiovaxID prolonged -- not delayed -- remission by more than one year.
For The Record
Los Angeles Times Monday, July 13, 2009 Home Edition Health Part E Page 5 Features Desk 1 inches; 47 words Type of Material: Correction
Cancer vaccines: An article in the July 6 Health section about vaccines used to fight cancer stated that the vaccine BiovaxID delayed remission of lymphoma patients after chemotherapy by more than one year, on average. BiovaxID prolonged -- not delayed -- remission by more than one year.
The vaccines don't measure up to other cancer therapies that have passed muster with the FDA in recent years, such as Herceptin, Gleevec and Rituxan, says Dr. John Glaspy, director of the Women's Cancers Program at UCLA's Jonsson Comprehensive Cancer Center. Gleevec, in particular, has revolutionized the care of the most common adult leukemia, known as chronic myeloid leukemia, raising five-year survival rates to 89% of patients taking the drug. Before Gleevec, patients' chances of surviving for five years with existing treatments were closer to 50%. "Those are huge breakthroughs in oncology that have made big impacts," Glaspy says.
Cancer vaccines have made comparable advances on the basic science front, but they have not yet translated into successful medicines. Yet researchers are reinvigorated by the recent successes because they suggest that, with combination therapies and careful patient selection, the vaccine strategy could work to fight cancer. "It's feasible," Glaspy says. "We're starting to see a few patients do well."
The ideal of therapeutic cancer vaccines still shimmers with promise: Imagine a medicine that's specific to a tumor and free of side effects. "If we can get the immune system to engage in this process, it works completely differently than any other cancer treatment out there. And the neat thing about the immune system is that it remembers," Emens says. "If we can get it to work, it has the potential to add a lot."
Even those stung with failure hold onto hope. "I remained convinced that the immune system is very important in the control of cancer," Morton says. "We just need to know what the right buttons are to push so that everybody responds."
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health@latimes.com
