Taking a cue from nature, investigators have set out to determine whether a new gene therapy for HIV can replicate a natural defense mechanism spawned by a genetic mutation, offering a new approach to fighting AIDS. And over the weekend researchers reported that a tiny, early-stage study produced initial signs of efficacy in suppressing viral load, helping to underscore the potential of the new T-cell strategy from Richmond, CA-based Sangamo.
Their work revolves around the understanding that the CCR5 gene plays a key role in ushering HIV into cells. Patients with a mutant version of the CCR5 gene, though, are known to be resistant to HIV. And researchers mimicked that process in the SB-728-T program, withdrawing T cells and having them modified by using zinc fingers to interfere with DNA found in the CCR5 gene.
A total of 10 patients were recruited for the trial. After four weeks of therapy 6 of them stopped taking their regular antiviral medications for 12 weeks. Of those 6, three saw their viral load drop, according to Reuters, with one--who already carried the gene mutation in one of the CCR5 genes--seeing it drop to undetectable levels. Significantly, an estimated 10% of all HIV patients have at least one copy of the mutant gene. No serious adverse effects were reported, add investigators, with a persistent smell of garlic being the most common side effect.
"We see a significant anti-viral effect," Samgamo Chief Executive Officer Edward Lanphier tells Bloomberg. "That's the big punchline here." Sangamo's shares ($SGMO) surged on the news.
"The data obtained in our treatment interruption studies are very exciting and represent significant progress toward a 'functional cure' for HIV/AIDS," said Dr. Carl June, the UPenn investigator in the study, who also directed a controversial and very high-profile T cell study in leukemia recently. "The statistically significant relationship between estimated modification of both copies of the CCR5 gene and viral load during the treatment interruption suggests that the next step is to increase the frequency of the modified cells in HIV-infected patients with the ultimate hope that if we do, we will achieve a 'functional cure' and eliminate the need for continued HAART."
- here's the Sangamo release
- read the story from Bloomberg
- and see the Reuters piece