He Inherited A Devastating Disease. A CRISPR Gene-Editing Breakthrough Stopped It

SARAH MCCAMMON, HOST:

There's big news today about the revolutionary gene-editing technique called CRISPR. For the first time, doctors have used CRISPR to help patients simply by infusing it into their bloodstreams. NPR health correspondent Rob Stein joins us now to talk about the details. Hey, Rob.

ROB STEIN, BYLINE: Hey there, Sarah.

MCCAMMON: OK, so first of all, if you would, remind us what CRISPR is exactly and how it's been used to try to cure diseases.

STEIN: Yeah, so CRISPR allow scientists to make very precise changes in DNA much more easily than ever before. So doctors think it could be used to treat lots of different diseases. In fact, doctors have already started using it to help patients suffering from devastating blood disorders, like sickle cell disease and beta thalassemia and have started trying to use it to treat a wide variety of cancers, even to restore vision to people blinded by a rare genetic disorder.

But until now, scientists have had to take cells out of the body, edit them in their labs, and then infuse the edited cells back into patients' bodies or inject it directly into the cells they're trying to edit. The big news today is that for the first time, they've just infused CRISPR into the bloodstream, like you said, and let it travel through the body to the cells that need editing on its own. So it's a big step forward.

MCCAMMON: Yeah, it sounds like a pretty impressive step forward. What was the disease that they tried this for?

STEIN: It's called amyloidosis, and it's a terrible disorder in which malformed proteins build up inside people's bodies, damaging vital tissues and organs like nerves and the heart. Patients often become disabled and eventually die from the damage.

I talked about this with Patrick Doherty (ph). He's 65 and lives in Ireland. His dad died from amyloidosis, so have two relatives and people he knows. And about a year and a half ago, he noticed something that really scared him.

PATRICK DOHERTY: The very tips of my fingers were totally numb. There was a continuous tingling, pins and needles in my hands.

STEIN: And he started then to get short of breath just by trying to walk his dog. Turns out he had amyloidosis, so he volunteered to let doctors test this new way to use CRISPR on him.

MCCAMMON: OK. So how did his treatment work exactly?

STEIN: Doctors infused instructions for the CRISPR gene editor into his bloodstream. It made its way to his liver and honed in on the gene producing the protein that was attacking his body. The CRISPR essentially acted like a - kind of a microscopic surgeon, cutting the gene and shutting off the bad protein. And doctors are reporting today that looks like it was safe for Doherty and five other patients and seems to have worked. The bad protein levels just plummeted. Here's Julian Gillmore. He's running the study at the University College London.

JULIAN GILLMORE: It worked incredibly well. It's incredibly exciting. It's - you know, it's doing what we hoped it would do extremely effectively. It's amazing.

STEIN: And Doherty agrees.

DOHERTY: I feel fantastic. And I feel better in terms of - like, I'm speaking to you from upstairs in our house. I climb stairs to get up and down here. I would have been kind of breathless. It's just phenomenal.

STEIN: Now, you know, it's important to note that doctors will have to follow Doherty and the five other patients who have been treated so far and treat a lot more patients to make sure this is safe and does really help patients. But if it does, it could change their lives and the lives of many other patients.

MCCAMMON: And what are the ramifications here, Rob? I mean, what - could this approach be used for other diseases?

STEIN: Yeah, yeah. You know, the disease Doherty has is a rare inherited condition. But Dr. Gillmore tells me that the same approach could also help patients struck by a much more common form of the disease that doesn't necessarily just run in families. And beyond that, this is a kind of proof of concept that CRISPR could be used to treat many much more common diseases, including heart disease, you know, muscular dystrophy and potentially brain diseases like Alzheimer's. So Patrick Doherty's experience could just be the beginning.

DOHERTY: That's NPR's health correspondent Rob Stein. Thanks so much, Rob.

STEIN: You bet.

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