美国国家公共电台 NPR 'Living Drug' That Fights Cancer By Harnessing Immune System Clears Key Hurdle（在线收听）

KELLY MCEVERS, HOST:

Cancer patients are a step closer to an entirely new way to fight their disease. It's something scientists call a living drug. Today a pharmaceutical company cleared a crucial hurdle toward offering the treatment widely to patients for the first time, starting with kids who have leukemia. NPR health correspondent Rob Stein is with us now to talk about this. And Rob, tell us what happened today.

ROB STEIN, BYLINE: Yeah, hi, Kelly. So a panel of outside experts assembled by the Food and Drug Administration spent the whole day reviewing an application from the drug company Novartis. Novartis wants the FDA to let the company start selling this treatment for kids and young adults with leukemia who've run out of other options. And this would be the first time the FDA has approved this entirely new way to fight cancer. In fact the FDA says it would be the first time they were approving anything that they would call a gene therapy product.

MCEVERS: What is that? How does it work? What makes it unique?

STEIN: Yeah, so you - we all know how we usually treat cancer. We either, you know, cut it out with surgery, or we poison it with chemotherapy or radiation.

MCEVERS: Right.

STEIN: And this is part of the hot new thing in cancer research, which is using the body's natural defense system, our own immune system, to kill cancer cells. Scientists - you know, in recent years, they've come up with some new drugs that can trigger the immune system to attack tumors. What this is is scientists are using genetic engineering to create tailor-made living cells to attack tumors. And that's why scientists are calling this a living drug.

MCEVERS: How do they do it?

STEIN: Well, it's really interesting and kind of complicated. So what doctors do is they remove very specific immune systems from people's bodies - known as T cells from their blood. And they take the cells, take them back to their lab. And they use genetic engineering to reprogram the genes in the cells to turn them into what you can kind of think of as like attack drones or laser-guided missiles that zero in on their cancer cells. And then the doctors - they infuse millions of these genetically modified smart bombs back into the patients' bodies so they can obliterate the cancer and hopefully leave the healthy cells, you know, unscathed.

MCEVERS: And has it worked?

STEIN: So far it looks really promising. You know, the company tested this on dozens of kids and young adults who had a type of leukemia called B-cell acute lymphoblastic leukemia. It's the most common form of cancer among kids in the United States. And these patients - either they hadn't responded to the traditional therapies, or they'd had a relapse and really had run out of any other options. And when they gave them this treatment, 83 percent of the patients went into remission. So an overwhelming majority of the patients went into remission. And this isn't the only cancer it seems to be working on. It seems to be working on some other cancers as well.

MCEVERS: Are there any dangers or side effects to the treatment?

STEIN: Yeah, you know, that is a concern here. This treatment can cause some pretty severe and potentially even fatal side effects. It can cause the immune system to sort of go into overdrive and attack the patients' bodies. Doctors call this a cytokine storm. And it can cause, you know, sometimes a dangerous swelling in the brain. In fact there were a handful of patients who died from this brain swelling when they were in a study sponsored by another drug company, a different version of this.

And so there are also some concerns about long-term side effects. The big concern is they genetically engineer these cells using a virus. And so so far, that all looks fine, but patients haven't really been involved that long. So there's some concern that, you know, we don't know what could happen in the future. And I guess the final big thing is this is not cheap. You know, it's a very complicated treatment to create, so it's going to cost a lot. I - you know, doctors have to tailor-make each treatment for each patient.

MCEVERS: Right.

STEIN: So we're talking hundreds of thousands of dollars for each infusion.

MCEVERS: Quickly, what happens next?

STEIN: So the FDA doesn't have to follow the advice of its advisers, but it usually does. And there are some other cancers - other companies developing similar therapies that are waiting in the wings to try to get their drugs to prove true.

MCEVERS: NPR health correspondent Rob Stein, thank you.

STEIN: Oh, sure.

(SOUNDBITE OF YUSSEF KAMAAL'S "LOWRIDER")