Researchers Develop New Attack on HIV

Science & Medicine | Researchers Develop Technique That Prevents HIV From Reproducing, Philadelphia Inquirer Reports
[Feb 11, 2008]

Researchers from the biotechnology company Virxsys and the University of Pennsylvania have developed a gene therapy technique that prevents HIV from reproducing, according to a study presented Wednesday at the 15th Conference on Retroviruses and Opportunistic Infections in Boston, the Philadelphia Inquirer reports.

For the study, the researchers removed CD4+ T cells from an HIV-positive person and inserted the cells into a gene that stops the virus from reproducing. The researchers then used a University of Pennsylvania patented technology to multiply the T cells one hundred-fold and put them back into the patient using a harmless version of HIV. The gene into which the researchers inserted the T cells prevents HIV from containing itself in a shell, making the virus unable to reproduce and form new HIV-infected cells. The study also found that HIV self-destructed when the gene was inserted back into the patient.

The study examined nine randomly chosen HIV-positive people and found that all nine had high HIV viral loads after undergoing the treatment but that most of the virus had mutated into harmless forms. A clinical trial among 54 HIV-positive people is ongoing to determine the safety of the technique, called VRX496, and the best dosages. None of the trial participants has experienced serious negative side effects, and many have suppressed HIV viral loads and increased their T cells.

The technique "raises hope" within the HIV vaccine research community that if a preventive vaccine is not developed, the technique could be used to control HIV among people already living with the virus, the Inquirer reports. Gary McGarrity, executive vice president for scientific affairs at Virxsys, said the "buzzword" in gene therapy research is "viral 'fitness'" and that VRX496 "diminishe[s] HIV fitness up to two years after treatment."

The possibility of the technique becoming an FDA-approved treatment is several years away, but Virxsys CEO Riku Rautsola estimated the potential cost for a one-time series of infusions would be $130,000, compared with the roughly $700,000 cost for lifetime treatment with antiretroviral drugs. Rautsola said the company hopes the treatment will become a "frontline therapy," adding that it "would clearly be better in terms of quality of life" for people living with HIV/AIDS (McCullough, Philadelphia Inquirer, 2/7).