"Our results suggest that it is not only the drug that sends the leukemia into remission, it's also the natural immune response," Levy said. "After starting imatinib, the anti-leukemia immune response gradually increases. However, it begins to weaken after it reaches a peak. This typically happens well into the treatment.
"Leukemia cells are still present, but in relatively low numbers that causes the immune response to wind down. Unfortunately, this is an ideal time for the cancer cells to develop drug resistance and render the therapy ineffective."
Best Time for Immune Response
Incorporating Lee's clinical data on immune response, Levy's model suggests that the immune response of the patients should be boosted at the time when their immune response starts weakening.
The authors suggest that such a stimulation can be provided in the form of "cancer vaccines," in which pre-therapy blood taken from patients is irradiated to kill active cancer cells, then introduced back to the patient. A strong stimulation of the immune system was shown to be active in vitro in Lee's lab experiments.
"The mathematical approach showed that it is imperative to connect the timing of the cancer vaccine with the individual profile of the immune response of each patient," Levy said. "The mathematical simulations suggest that a vaccine administered within the initial months of the treatment will have no effect on the progression of the disease. On the other hand, a well-timed vaccine can potentially cure the disease."
Individual Therapy Plan
But the dynamics of each patient's immune response differ. That's where the math comes in, says Levy. "We can find rules for application to a specific patient. We can measure each patient's parameters to find when the dosage will b
|Contact: Ellen Ternes|
University of Maryland