In October, researchers reported in the journal Nature Medicine of their successful tests of a DNA vaccine in mice. In January, further evidence from a trial of the vaccine demonstrated that it could protect at least some of the mice for very long periods of time.
The research focused on acute promyeloctyic leukemia which is currently treated with chemotherapy which cures about 75 percent of cases.
The researchers used a mice model of the disease, exposing one experimental group to the vaccine and another experimental group to the vaccine and chemotherapy. In half the mice receiving the combination of the vaccine and chemotherapy, half the mice lived an additional 300 days — the equivalent of 25 human years.
The vaccine uses fragments of a faulty gene found in cancer cells to train the immune system of the animals to recognize and destroy cancerous cells.
As lead researcher Dr. Rose Padua told the BBC, this sort of approach might one day help improve survival odds for those patients who don’t respond to chemotherapy alone,
Currently, despite a major improvement in the survival of APL patients, a cure is still not achieved in all patients. The DNA based vaccine has proven to induce protective immunity. This example of a target therapy in an APL animal model may provide us with an alternative therapy, which if translated to humans, will improve quality of life and survival rates for leukemia patients.
Obviously, any human application would still be many years away.
Source:
Hope for leukemia vaccine. The BBC, January 7, 2004.
DNA drug offers leukaemia hope. The BBC, October 20, 2003.