Lung Cancer Vaccine May Offer Hope for Patients
Wednesday, December 10, 2008
There is no cure for advanced lung cancer. Patients usually die within a year of being diagnosed. But there could be some hope on the horizon. A San Diego biotech company has developed a vaccine it hopes will extend the lives of lung cancer patients. The vaccine has shown promise in early tests. It's now in the final phase of clinical trials. KPBS Health Reporter Kenny Goldberg has the story.
Once a month, lung cancer patient Cookie McNamara comes to the UCSD Moores Cancer Center.
Nurse and McNamara: What we're gonna do here, is give you the injection, and I think they did it two times before, this is gonna be the third time.
McNamara is taking part in a clinical trial of a vaccine for people with advanced non-small cell lung cancer.
Nurse and McNamara: Stretch a little bit your skin, a little pinch, and let's put the medication in.
Nobody knows whether McNamara is getting the vaccine or a placebo.
McNamara was diagnosed with end stage lung cancer in January 2007. She went through 12 weeks of chemotherapy. Then, her oncologist told her she was eligible for the clinical trial.
McNamara: She offered it to me, and I didn't even hesitate. I have such trust in the doctor. Like she says if someone offers you a silver bullet why wouldn't you take it?
People with advanced lung cancer are looking for silver bullets. That's because current therapies just aren't effective.
Dr. Luda Bazhenova is McNamara's oncologist. She's the principal investigator for the San Diego wing of the study.
Dr. Bazhenova: It's a cancer that kills more people than breast, colorectal, prostate, and maybe some other couple of cancers combined. So if we are able to make a dent in cancer overall, this is the disease we should try for first.
Dr. Habib Fakhrai: When I started in cancer, I was hearing that patients who have cancer are immune suppressed. And immediately it came to my mind that somehow we have to block the immune suppression in these patients if we are going to have an effective vaccine.
After trying some other agents, Fakhrai came upon a molecule produced by tumor cells.
The molecule acts as a cloaking device against the body's immune system. It basically disables the immune cells. That allows cancerous tumors to grow, and eventually kill the patient.
Fakhrai discovered the molecule has no effect on activated immune cells. So he designed a vaccine that contains molecules that have been genetically altered to block their immune suppressive properties. Fakhrai explains what happens when the drug is injected under the skin.
Fakhrai: We create a micro environment the size of a teardrop. All the body is immune suppressed, but that micro environment is not. When immune cells go there, they become activated because there is no immune suppression in that little micro environment.
And once they become activated, they proliferate.
Fakhrai: And they can stop the tumor in its track, and the tumor does not grow anymore. And the patients can live with their cancer for many years.
In the phase two trial, 59 percent of those who received the vaccine were still alive more than three years after their diagnosis. Most end-stage lung cancer patients don't survive one year.
What's more, there were no side effects from the vaccine. The goal of the phase three trial is to confirm these results. Unfortunately, Cookie McNamara may not be around to see what happens.
Since we first spoke with her, she's learned that her cancer has progressed. As a result, she's been removed from the trial. Nonetheless, McNamara says she's proud to have been a part of it.
McNamara: We're all gonna die. And the only thing I can do, you know, is try to do it in the most graceful way possible, and you know, hopefully helping somebody.
Kenny Goldberg, KPBS News.
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