Obstacles in Using Gene Editing to Cure HIV

Segment Description: Eric Daar, MD, chief of the Division of HIV Medicine at Harbor-UCLA Medical Center, discusses the obstacles associated with new research and technology in the pursuit of finding a cure for HIV.

Interview Transcript (modified slightly for readability):

“I think there are a few issues [with editing genes to cure HIV], and 1 of them is, you need to be able to do this with a pretty high level of activity. You need to identify a lot of cells, be able to effectively edit their genes in a substantial proportion, and then put them back in and hope that they ultimately takeover even though we know that these people have not been blasted with chemotherapy to wipe out their own cell population.

And so, I think some of the obstacles is creating a situation where this can be done effectively and efficiently so that you have a large proportion of cells that have been altered that can then be reinfused. Or if you can come up with a way to actually do it in the person, or to put them into stem cells that can then be transfused into the person, and hopefully, then continue to expand so that their own cells are increasingly missing the CCR5.

I think those are going to be the obstacles; there have been some clinical data with some of these strategies that have suggested little hints of promise but nowhere close to a cure based on what’s been tested so far.

I think the other obstacle in addition to creating a system that’s extremely efficient and proving that it actually makes a difference, the other obstacle that everybody is struggling with is safety. Altering somebody’s genes could potentially pose some risks, especially if there’s some off-target alterations that occur and that you don’t just get the CCR5, but you perhaps hit other genes that might put people at risk for complications down the road. And so, this is going to be looked at very carefully, will need to be regulated, and studies will have to start small and get big if they demonstrate evidence of efficacy with long-term follow up for safety—not our traditional studies where you do it for 1 year and see if everything’s okay because the consequences of editing someone’s genes may not become apparent for many years.

I would say the case is that this is very, very early in the pursuit of this type of treatment strategy in patients. With the goal mostly being trying to cure people or at least put them in remission for HIV so that they don’t need to remain on antiretroviral therapy. The bar is really high, I think this is an extremely important avenue of research—to try to cure people. But we have to balance whatever the risks and costs are, against what our current strategies are for managing HIV, and that’s often 1 pill a day with no side effects and the chance for a long healthy normal life.”