In this video from Motley Fool Live, recorded on March 15, contributors Brian Orelli and Keith Speights discuss the difference between ex vivo gene editing (outside the body) and in vivo editing (within the patient). CRISPR Therapeutics (NASDAQ:CRSP) and its partner Vertex Pharmaceuticals (NASDAQ:VRTX) have mastered ex vivo gene editing, but the strategy is limited to diseases where cells can be manipulated outside the body. Up-and-coming gene editing companies may have a bigger opportunity if they can master the in vivo technique.

Brian Orelli: Sticking with sickle cell disease, multiple companies are trying to catch bluebird bio (NASDAQ:BLUE) using CRISPR to edit DNA and to treat the disease. CRISPR Therapeutics and Vertex are furthest along; they already have data that's shown that they can cure patients at least in the short term, meaning maybe months or maybe that date out to a year I'm not sure. Editas Medicine (NASDAQ:EDIT) just started a phase 1/2 clinical trial for sickle cell disease. I don't believe they have any data yet. These companies are doing this ex vivo, so that's outside of the body. Basically, they take the cells out of the patients, take the bone marrow out of the patients. They do the CRISPR and then they put the bone marrow back in.

Last week, Intellia [Therapeutics] (NASDAQ:NTLA), which is the third major CRISPR editing company, released data that showed that they can edit bone marrow in vitro. They're just putting the CRISPR Therapeutics in a cassette that goes into the into the body. You just do an infusion and then it goes if finds the bone marrow and changes the cells. But of course, this was in mice. They haven't cured humans yet. Can you talk about the advantages of in vivo versus ex vivo using CRISPR?

Keith Speights: Yeah. There actually are several advantages for the in vivo or in-the-body approach. It's a lot easier to manufacture for one thing, and it's safer actually. You know you have to think about it. The ex vivo approaches, basically, they have to essentially do bone marrow transplantation. They are taking all the blood out and engineering it and putting it back in.

Orelli: They're basically giving people chemotherapy.

Speights: Yeah, basically.

Orelli: Not basically -- they are giving people chemotherapy to, instead of trying to kill the bone marrow that's cancerous, they are trying to kill the bone marrow to make room for the new cells you want to put in.

Speights: Right, and they can administer more treatments with this approach as well, and that's another advantage. They can basically do more treatments so that CRISPR edits more cells. That's good news because that can make the ultimate efficacy higher. There's a lot of reason for hope about the potential for this and others. There's a lot of good news really for patients with sickle cell disease and beta thalassemia, which are two similar rare genetic blood disorders.

Obviously, CRISPR Therapeutics, and its partner Vertex are farthest along in their clinical testing, they have reported some good results so far. Editas medicine has a promising approach that the company thinks could be even safer, more effective than CRISPR's approach because of where it focuses on doing the gene editing. They are in phase 1/2 testing for sickle cell disease and hope to later expand into beta thalassemia. Intelia's approach, the in vivo approach, could be the safest and most effective of all, but it's behind the others. But there's good news all the way around. I think there's possibilities for success for all of these companies involved, by the way, just as a disclosure, I own shares about Editas Medicine and Vertex Pharmaceuticals. But I'm actually rooting for all of the companies in this space.

Orelli: I own shares of Vertex. The other thing I think that the in vivo really gives you that the ex vivo doesn't, is that there's a lot of different diseases that you can only treat in vivo. There's only a limited number of diseases where you can pull the cells out and then manipulate them in the laboratory and then put them back in. Kidneys, livers, all those are going to require In vivo to treat the disease with CRISPR. This is a good first step for CRISPR to at least be able to treat the bone marrow.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.

Source link