Researchers present Phase II HIV gene therapy trial data at CROI 2010

February 19, 2010

In the study, seven of eight subjects experienced a decrease in viral load set point and one subject experienced prolonged, complete control of HIV viremia for more than 14 weeks in the absence of HAART. The study looked at Lexgenleucel-T infusions in HIV-1 infected individuals prior to being taken off their antiretroviral treatment regimens as part of the study design's scheduled treatment interruption.

Researchers from the University of Pennsylvania School of Medicine presented today the results from an ongoing Phase I/II open-label clinical trial of Lexgenleucel-T at the 16th Conference on Retroviruses and Opportunistic Infections (CROI) in San Francisco, CA.

Lexgenleucel-T is a cell and gene therapy product being investigated for the treatment of . The current study examined the effect of Lexgenleucel-T infusions in HIV-1 infected individuals prior to being taken off their (HAART) regimens as part of the study design's scheduled treatment interruption. In the study, seven of eight evaluable subjects experienced a decrease in viral load set point and one subject experienced prolonged, complete control of HIV viremia for more than 14 weeks in the absence of HAART. Viral load set point is the HIV RNA value specific for each infected individual in absence of anti-retroviral drug control. Higher viral load set point is correlated with more rapid to AIDS.

"We are excited to see these responses using autologous transfer of CD4+ T lymphocytes genetically modified with VRX496TM, a HIV-based lentiviral vector encoding for a RNA antisense targeting HIV env. These are subjects who were taken off of their antiretroviral treatment and are showing a better control of their infection as demonstrated by reduced viral load set points," said Pablo Tebas, M.D., director of the Adult AIDS Clinical Trials Unit, who presented the results at CROI. "Further study is needed to see whether these types of results will translate into a delay in disease progression."

In the current study, several administrations of Lexgenleucel-T, each comprising approximately 1010 autologous CD4+ T cells transduced ex vivo with VRX496TM, were administered to 17 HIV-1 infected subjects who were fully suppressed on HAART. Each subject received three to six separate infusions over a period up to 13 weeks. Six weeks after the last infusion, eligible subjects underwent a scheduled treatment interruption to evaluate timing to HIV RNA recrudescence, changes in viral load set point and changes in CD4 T cell count. Of the 17 subjects who received infusions, 13 (76%) underwent the scheduled treatment interruption. Eight of these 13 subjects (62%) were evaluable for the efficacy endpoint. Overall, 7 of 8 (88%) of the evaluable subjects had a decrease in viral load set point ranging from -0.26 to -0.98 Log10. One subject maintained a complete control of HIV viral load below the limit of detection (50 copies/ml) and a CD4+ cell count greater than 1200 cells/µL for over 14 weeks.

"It is notable that all patients on the protocol had elevated CD4+ counts after treatment with Lexgenleucel-T," said Carl June, M.D., professor of Pathology and Laboratory Medicine. "Achieving a complete control of HIV recrudescence following HAART interruption for over 14 weeks is, indeed, remarkable."

Explore further: HIV Hiding from Drugs in Gut, Preventing Immune Recovery

Related Stories

HIV Hiding from Drugs in Gut, Preventing Immune Recovery

July 31, 2006

UC Davis researchers have discovered that the human immunodeficiency virus, the virus that causes AIDS, is able to survive efforts to destroy it by hiding out in the mucosal tissues of the intestine. They also found that ...

HIV measurement is questioned

September 27, 2006

Preliminary U.S. research indicates the HIV RNA level in untreated HIV-infected patients has little value in predicting the rate of CD4 cell count decrease.

Selenium supplements may contribute to reduced HIV viral load

January 22, 2007

Taking daily selenium supplements appears to increase the level of the essential mineral in the blood and may suppress the progression of viral load in patients with HIV infection, according to an article in the January 22 ...

Recommended for you

Machine Translates Thoughts into Speech in Real Time

December 21, 2009

(PhysOrg.com) -- By implanting an electrode into the brain of a person with locked-in syndrome, scientists have demonstrated how to wirelessly transmit neural signals to a speech synthesizer. The "thought-to-speech" process ...

Quantum Theory May Explain Wishful Thinking

April 14, 2009

(PhysOrg.com) -- Humans don’t always make the most rational decisions. As studies have shown, even when logic and reasoning point in one direction, sometimes we chose the opposite route, motivated by personal bias or simply ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.