The DCVax vaccine is
a personalized cancer
treatment that uses a
patient's own tumor cells.
Banking on Success: Keeping Tumor Tissue for Use in Cancer Treatment
May 13, 2010
by
Heather Mayer, DOTmed News Reporter
When Robert Gibbs, 41, was diagnosed with a Grade 2 brain tumor in 2004, he didn't have many treatment options other than the traditional chemotherapy, radiation and surgery. But unfortunately for Gibbs, his 2005 surgery didn't completely wipe out the cancer, and in 2008 it was back.
"I had everything going for me," he said. "And it all came to a screeching halt."
His second surgery left him legally blind and searching for a better treatment option. It was then he turned to a clinical trial testing a tumor vaccine called DCVax.
"Other than being legally blind due to the tumor, I'm going through no other treatment," Gibbs, now six years cancer-free, told DOTmed News. "[The vaccine] works."
The DCVax is a personalized cancer treatment that uses a patient's own tumor cells, after surgery, to fight off remaining cancers, working like any other vaccine, explained Linda Powers, chair of the Northwest Biotherapeutics board, which manufacturers the vaccine.
"We found, although heartbreaking, a lot of patients are getting in touch with Northwest after the tumor tissue was thrown away," Powers said of patients trying to participate in the company's third clinical trial, currently underway.
Gibbs and his wife, Barb, co-founded the Florida-based national organization, Miles for Hope, in order to raise money for brain cancer research and to help spread the word about banking tumor tissue, which can be used in a treatment vaccine. The organization also helps people access clinical trials, which could save their lives, as it did for Gibbs.
"If it wasn't for family or friends with frequent flyer miles, we may not have opted to participate [in the trial]," he said. "[Miles for Hope] makes sure people have access to cutting-edge treatment to save lives."
PERSONALIZED THERAPY
Northwest Biotherapeutics, is not the first to come out with a personalized cancer vaccine. Dendreon was the first company to get FDA approval to commercially market a personalized vaccine for prostate cancer last month. But Northwest Biotherapeutics is following the trend of immune-system-based treatments.
Unlike Dendreon, Northwest Biotherapeutics uses individual patient tissue as opposed to a tumor-specific antigen, making DCVax even more personalized, explained Linda Liau, vice chair of neurosurgery at UCLA and the trial's lead researcher.
"Everyone has written off immune therapies," said Powers. "Finally, after all this time, the research community has continued to work on understanding the biology...Dendreon had FDA approval for immune therapy. There will be a flood of more immune therapies."
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.
Currently, more than 20 percent of patients reached the six-year mark or more, said Powers.
"With conventional treatment -- surgery, radiation, chemotherapy -- no one makes it to six years," she said.
But because the vaccine is still in clinical trial, patients also must go through traditional treatments, Powers said.
"You have to give standard of care," she said. "If something is experimental, it can only be additional."
TUMOR BANKING
What makes the DCVax vaccine possible is the utilization of a patient's tumor tissue and blood sample. In order for the vaccine to be created, patients need to store their tumor tissue after surgical removal in a tissue bank, not unlike an umbilical cord bank or blood bank.
After surgery, hospitals collect a small sample of the tumor for their archives, but that does not belong to the patient, explained Powers.
"Hospitals only store a small sample," she said. "Today, the rest gets thrown into the trash can," which makes a vaccine treatment impossible.
"Once tissue is out of the patient and the hospital takes a sample, that's it," she said. "Patients can't access it. Who does it belong to? Who gets to use it? Not the patient."
For this reason, HealthBank, a bio banking company, recently announced that it will store tumor tissue. According to HealthBank, the initial process of freezing a patient's tumor tissue and the first year of storage costs $1,995. After the first year, it costs $195 per year of storage.
In order for a patient to store his or her tissue, arrangements are made prior to surgery to put together a kit, which is delivered to HealthBank, or a similar storage bank, like Wake Forest University Baptist Medical Center or Penn State Hershey Cancer Institute, and then delivered to a doctor or clinic where the tissue will be used for treatments, like personalized vaccines.
But tissue banking offers more opportunities than just personalized medicine. Researchers can genetically profile a patient's tumor, which can evaluate the cancer and its prognosis. This allows doctors and researchers to cater treatment to a specific patient.
Another promising possibility of tissue banking is chemo-sensitivity testing, which can help identify which drugs the tumor will respond to. This allows patients to avoid unnecessary chemotherapy treatments.
"With chemo-sensitivity testing, you can test a particular drug regimen directly in a lab dish and learn what works the best," said Powers. "Most cancer drugs only work, clinical research has shown, in 25 to 30 percent of patients, but all of the patients get the toxicity. Instead of finding out the hard way, you can start to find out with chemo-sensitivity testing."
A WONDER DRUG?
Cancer experts aren't dubbing the investigational personalized vaccine the wonder drug just yet. In fact, it may never be used on its own as a cancer treatment, said William Chambers, director of clinical research and immunology at the American Cancer Society.
"I would hesitate to call it the wonder drug," he told DOTmed News. "They've done a really great job, and let's continue to look and see where it goes from here."
Chambers pointed out that the researchers were smart to include vaccination as a part of treatment for brain tumors. The vaccine is a good way to attack certain elements of the tumor that are hard to get to through surgery or chemotherapy.
But ultimately, a multiple-strategy approach is best, said Chambers.
"With most tumors, it's a pretty good idea to have a one, two ... three punch because of the ability of tumors to change," he said.
COST OF LIFE
Because Gibbs was part of a clinical trial, his treatment has been completely free, barring travel costs. Powers was unable to disclose how much vaccine manufacturing costs Northwest Biotherapeutics, but she said it's very affordable.
"Our pricing will be dramatically lower than pricing that Dendreon announced," she said.
Dendreon charges $31,000 per infusion; a full-course treatment includes three infusions over the course of one month.
She also pointed out that analyses indicate the vaccine will fall "well within the zone for reimbursement."
While the widely held belief is that personalized medicine is extremely expensive, Powers explained that for each patient, Northwest Biotherapeutics can manufacture three years worth of vaccination, making the process cost-effective, similar to mass manufacture of prescription pills.
"The concept is, the manufacturing itself is really expensive because it's personalized," she said. "But storage is cheap. Northwest makes the biggest batch it can make from a quantity of tissue and freezes it in single doses. After that, it's cheap; it turns into an off-the-shelf product."
Patients in the trial receive a vaccination every couple of weeks starting six weeks after surgery. The dose administration is reduced to every couple of months and then twice a year until the product runs out.
"The amount of tissue is the limiting factor," Powers said.
Northwest Biotherapeutics will be able to even further lessen its costs by making the process completely automated. Currently, the FDA has approved partial automation for the company, Powers said.
"Costs are already manageable to charge less than current antibodies that are not personalized," she said.
But when it comes to the patient, this vaccine would be covered by insurance.
MOVING FORWARD
Due to FDA policy, clinical testing for drug treatments can focus on only one disease at a time. In the case of DCVax, it is only being tested on brain cancer, but that doesn't mean it wouldn't work on other cancers, explained Powers.
"It should work on any type of cancer," she said. "We're just restoring the natural function of the immune system."
The patients in the Northwest Biotherapeutics trials all had Grade 4 tumors, with a few Grade 3 exceptions like the reappearance of Gibbs' condition. If approved for commercial sale, DCVax would only be for Grade 4 tumors, explained Liau.
"It's up to the FDA, what they feel is safe," she said. "Scientifically there is not a huge reason to think it wouldn't also be applicable [to lower-grade tumors]."
A successful personalized cancer vaccine blows the door wide open for personalized medicine and immune therapies, said Liau.
"If we're able to show efficacy, I think it really does help to transition the concept of personal medicine into reality," she said. "One reason we don't have a cure for cancer yet is because not every cancer is the same. There's not going to be one drug for all types of brain cancer."