Sangamo's gene editing tech tailors T cells to resist HIV, points to 'cure'

University of Pennsylvania's Carl June

Gene editing pioneer Carl June at the University of Pennsylvania is back in the headlines. The academic investigator--heralded for his work on a gene editing technique now being tested for cancer--led a team of scientists who successfully used zinc finger nuclease (ZFN) technology from Sangamo to tailor their T cells, essentially locking a back door used by the lethal virus. And the tiny human study may open the door to a radically new way to fight off HIV and AIDS, which has killed tens of millions of people around the world, raising the prospect that a functional cure may eventually be developed.

June and his team followed a trail of clues that had been carefully tracked in recent years. About one in 10 people have a genetic mutation in one of their two copies of the CCR5 gene that makes their T cells resistant to invasion by HIV. One in 100 patients has two "broken" copies of the gene, making them virtually immune. And in a study funded both by the NIH and Sangamo ($SGMO), which is using its technology in a variety of clinical programs, the scientists were able to use these zinc finger scissors to confer the same kind of protection to T cells which were extracted from patients, edited and then infused.

This science is still at an early stage, though, and isn't perfected yet, getting it to work on the CCR5 gene in about a quarter of the cells extracted, according to Nature. In the study of 12 people carrying HIV, the investigators selected 6 with normal T cell counts and interrupted their regimen of HIV-subduing cocktails. Their T-cell count stayed high for weeks and the viral load increased at a slower rate. One patient had a reaction to the transfusion.

Importantly, the modified T cells made their way to key places in the body, like the gut, where reservoirs of HIV accumulate.

"This study demonstrates that ZFN-modified cells can be safely administered back to the individual; are able to persist and circulate throughout the body to key reservoirs of HIV infection; and show preferential survival over unmodified cells when antiviral drugs are withdrawn, potentially keeping the virus under control without the use of drugs," says June in a statement. "Our experience reinforces our belief that an immunological approach is a promising approach to enable functional control of HIV infection and eliminate the need for lifelong ART."

For Sangamo, the high-profile study--which made headlines around the world on Wednesday evening--offers important proof-of-concept evidence of the potential of their gene editing technology. June and other academic investigators have already made waves with a new approach to redesigning T cells to attack cancer, an approach that has drawn in Novartis ($NVS).

Now the question is which biopharma company will come along to push this new attack on HIV. 

- here's the release from Sangamo
- read the story from Nature