Researchers Closer to a Functional Cure for HIV

New clinical trial results suggest that a "functional cure" for HIV is one step closer to becoming reality.

That's the news that Gary Blick, AAHIVS, Medical & Research Director of CIRCLE CARE Center and Chief Medical Officer of World Health Clinicians, presented on March 6 in Boston at this year's Conference on Retroviruses and Opportunistic Infections (CROI 2014), which was held from March 3-6, 2014.

"Sangamo has been at the forefront of this breakthrough proprietary therapy, and I'm happy to be a part of it," said Blick. "We're reaching a new frontier in the search for a functional cure for HIV, in which HIV-infected individuals may someday stop their HIV medications without any virus detectable in their blood."

In clinical trials led by Sangamo BioSciences, and in which Blick is an investigator, along with a study related to the trials that was published in the New England Journal of Medicine, HIV-infected subjects were intravenously infused with billions of genetically modified CD4+ T-helper cells (SB-728-T). These cells were subjected to Sangamo's proprietary genome editing technology, otherwise known as zinc finger nuclease (ZFN), in an effort to reduce the HIV viral load (VL), or the amount of the virus found in a subject which exhibits an ability to kill existing cells and to replicate itself. The CD4+ cells are genetically modified in an attempt to render them resistant to the HIV virus, and to prevent its spread.

"The achievement of more than seven months of ongoing functional control of viral load without ARV and the progress that we are making in understanding how to best deploy this novel therapy are very exciting," said Blick. "As data suggests, we are on the cutting edge of finding necessary solutions to providing patients with functional control of the virus."

In the FDA Phase 1 study published in the NEJM, 12 subjects were divided into two cohorts of six subjects. The first cohort consisted of individuals who demonstrated adequate recovery following ART and then received billions of genetically modified T cells followed by a treatment interruption (TI) from their antiretroviral therapy (ART), and the second cohort consisted of subjects who demonstrated inadequate recovery following ART. The latter cohort remained on ART throughout the study.

The study demonstrated that an individual's T cells can be safely engineered to make him or her resistant to HIV infection using ZFN-based genome editing technology and safely infused resulting in decreases in HIV viral load off ART and one subject whose viral load became undetectable.

Blick reported in a separate study that CD4 cells can be significantly increased, viral load can be decreased as much as 90 percent, and the count of ZFN-modified CD4 cells can be increased using a chemotherapeutic agent known as Cyclophosphamide (CTX). Two of three subjects treated with the highest dose of CTX remain on TI for 11 and 12 weeks with stable or lowered levels of VL.

Blick also updated the status of one of his patients from another study who has demonstrated ongoing control of VL with nearly undetectable levels of HIV for 31 weeks without ART.

For more information about World Health Clinicians, please visit www.worldhealthclinicians.org. For more information about Sangamo BioSciences, Inc., please visit www.sangamo.com.

Winnie McCroy is the Women on the EDGE Editor, HIV/Health Editor, and Assistant Entertainment Editor for EDGE Media Network, handling all women's news, HIV health stories and theater reviews throughout the U.S. She has contributed to other publications, including The Village Voice, Gay City News, Chelsea Now and The Advocate, and lives in Brooklyn, New York.

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