El depositar en éxito: Mantener el tejido fino del tumor para el uso el tratamiento del cáncer
por
Heather Mayer, DOTmed News Reporter | May 13, 2010
The DCVax, which is in its third stage of clinical trials, sends a message to the entire immune system to fight remaining tumor cells, literally picking up the pieces of the tumor not removed through surgery.
Researchers found that the immune system could fight off everyday infections -- influenza, colds, pneumonia -- but it was obviously succumbing to a tumor. What they discovered was that the dendritic cells or the "generals" of the immune system, as Powers explained, were not getting the message to fight off the malignant tumor.
"The immune system is keeping you healthy other than your cancer," Powers said. "That's the perplexing thing. Why is it not doing the job on cancer?"
"The problem in the body is not a lack of dendritic cells," she said. "It's that they're sitting around on a battlefield not receiving orders. The signals are not getting through. Tumors have a variety of ways of blocking signals."
The vaccine not only tells the dendritic cells to shift out of surveillance and into attack mode, it also provides the immune system with the biomarkers of the tumor, which come from the patient's tumor tissue. This tells the cells what they need to attack.
Once these signals are received, "they go right to work," Powers explained. "They do their normal job in a normal way."
What differentiates this type of cancer treatment from traditional methods like radiation and chemotherapy is the vaccine merely restores the natural function of the immune system, which has been interfered with by the tumor. There are no chemicals or drugs involved, eradicating the severe side effects from traditional cancer treatments.
"It works like a regular vaccine," Gibbs said. "What makes it different is that it's patient-specific. There's no rejection [from the body] and no toxic side effects."
The only reported side effects have been fever, skin irritation at the injection site, fatigue -- side effects similar to any vaccine, said Liau.
While hundreds of clinical trials have not reported toxicity with dendritic treatment, Liau pointed out that there is always a possibility of seeing side effects later on, especially with an autoimmune response.
"When you induce the immune response against its own tumor, the concern is the risk that you can over-activate it against its own normal tissue," she said. "We haven't seen that...The thought is that tumor tissue is so different from a patient's own normal brain tissue that the immune system can differentiate [the two.]"
Northwest Biotherapeutics has reported from previous trials that patients who received standard treatment in addition to the vaccine lived, on average, 36 months after diagnosis, compared with just 14 to 16 months for those who did not receive the vaccine.