Thursday, September 10, 2009

Hope for Vaccines?

A couple of items in the cancer world recently about cancer vaccines.


The idea of a vaccine is so intriguing to me. When a met with Dr. C, the lymphoma specialist, soon after I was diagnosed, he told me there were a lot of treatments for fNHL being developed, including a vaccine (see one of my very early posts -- I can still remember how excited I was at the idea). Vaccines in general work by giving a weakened or dead sample of a disease to a patient, allowing the body's immune system (usually its T-cells) to recognize this harmless shell of the disease and develop a way to kill it off. Then, when the real version of the disease invades the body, the T-cells already know how to deal with it, and kill it off before it can get out of hand.


Vaccines for cancers are basically the same. Take a sample of the cancer cells from an individual patient, find a way to get T-cells to attack it (maybe by giving modified T-cells that won't let the cancer cells slip past, maybe by signalling the patient's T-cells to attack), and put it all back into the patient. It should work, in theory.


Lots of research going on now is identifying the proteins and other features of cancer cells that make T-cells see the cancer cells as "safe," and thus just leave them alone. All of that should help in developing vaccines. So far, clinical trial results on existing vaccines have been pretty tepid. Some success, but not nearly what had been hoped for.


Part of the reason the success has been so slow is the lack of funding for immunologic research, says one expert in an article published in the New York Annals of Science, which recently had a special issue of papers from a Cancer Vaccine Symposium. According to this expert, lots of what we know about curing cancer comes from immunologic research -- examing stuff like how certain proteins on cancer cells fool the body into thinking they're harmless. He cites Rituxin and stem cell transplants as having been possible because of that kind of research. But, he argues, there is so little money available for that kind of research that a very promising approach is being wasted. Vaccines, he says, would attack cancer from many different paths; right now, most treatments only attack by a single path, which gives the cancer cells lots of opportunities to escape. (They're sneaky things, those cancer cells. Like Steve McQueen.)


Another expert argued recently that the reason vaccines haven't had much success is because the clinical trials are being designed incorrectly. This one is an opinion article, so it's not based on original research. But the author does have some credentials for having the opinion. The link goes to the journal Nature, a top-flight science journal, but it only gives an abstract. From the quick summary, he says that studies show that cancer vaccines should work in theory, but that the clinical trials with human patients aren't working, which leads him to think it's in the trials, not in the vaccines, where we could find the problem. He notes that, because of the failed trials, people are getting skeptical that vaccines will work.


Both of these articles give me some hope for vaccines. The idea of a vaccine makes a lot of sense -- use the body's own natural defenses, rather than adding harmful chemicals that shouldn't be in there. Whether lack of funding, or problems figuring out the best way to test and administer the vaccine, it seems like some outside problem is getting in the way.


We can't let that happen. We almost lost Zevalin because of negative outside forces unrelated to the treatment's effectiveness. I don't know if some vocal people will step forward and demand that a lymphoma vaccine gets some attention, but based on Dr. C's infectious excitement 19 months ago, there certainly seems like there's some support out there.

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