VRC01 antibody prolonged time to HIV viral rebound after treatment interruption

July 25, 2017, The U.S. Military HIV Research Program

A new study has shown that infusion of a broadly neutralizing antibody (bNAb) in virally suppressed, early treated volunteers was associated with a modestly delayed rebound of HIV after interruption of antiretroviral therapy (ART). The study, the first randomized controlled trial to demonstrate this effect of VRC01, was led by the U.S. Military HIV Research Program (MHRP) of the Walter Reed Army Institute of Research (WRAIR) and the Thai Red Cross AIDS Research Centre. MHRP presented findings from the study today at the 9th IAS Conference on HIV Science in Paris, France.

The study, called RV397, is part of a portfolio of MHRP's HIV remission research that seeks to find treatments to suppress the virus without a need for lifelong ART. Researchers evaluated the use of VRC01 in a small cohort of Thai men who were diagnosed and initiated ART within the first month of HIV infection, and who had been virally suppressed for about three years.

"This is the first time that the VRC01 antibody has been evaluated in people who started ART during acute HIV infection," said Dr. Trevor Crowell, the MHRP research physician who presented the findings. "We hypothesized that VRC01 might be more effective at suppressing HIV in the bloodstream of these volunteers than had been observed in people who started ART during the chronic phase of infection. These volunteers had a smaller HIV reservoir and less viral diversity, meaning they were less likely to have pre-existing resistance to the antibody."

Thirteen volunteers with undetectable viral loads were randomized into an intervention group that received VRC01, a broadly neutralizing antibody that inhibits multiple strains of HIV by adhering to the CD4 binding site on the virus. Five volunteers were randomized into a placebo group. Volunteers received infusions at the time of ART interruption and every three weeks thereafter, up to 24 weeks. If virus was detected in their blood, the infusions were stopped and ART restarted.

There was a delay in viral load rebound in people who received VRC01, which occurred at a median of 26 days versus 14 days in the placebo group. Seventeen of the 18 volunteers experienced viral rebound and reinitiated ART. One participant who received VRC01 was virally suppressed for 42 weeks post-treatment interruption, however within the last few days his viral load has become detectable.

"Although the delayed time to viral load rebound with VRC01 seen here is likely not clinically significant, it taught us two important lessons," said Dr. Jintanat Ananworanich, Associate Director for Therapeutics Research at MHRP. "It provides the basis for future studies in early treated people with combination bNAbs of higher potency, and we can now investigate the samples from this study to identify factors that might have contributed to the delay in rebound."

This is one of several functional cure studies MHRP is conducting in its acute infection cohort, RV254/SEARCH010, which is a collaboration with the Thai Red Cross AIDS Research Centre to identify acutely infected individuals and place them onto ART immediately. Researchers have found that this very early initiation of ART results in immune restoration and a very small or undetectable reservoir of HIV DNA.

Explore further: HIV antibody infusion safely suppresses virus in infected people

More information: Abstract: Tuesday, July 25, 2:30-4:00 pm: Dr. Trevor Crowell, "HIV-Specific Broadly-Neutralizing Monoclonal Antibody, VRC01, Minimally Impacts Time to Viral Rebound Following Treatment Interruption in Virologically-Suppressed, HIV-Infected Participants who Initiated Antiretroviral Therapy during Acute HIV Infection"

Related Stories

HIV antibody infusion safely suppresses virus in infected people

December 23, 2015
A single infusion of a powerful antibody called VRC01 can suppress the level of HIV in the blood of infected people who are not taking antiretroviral therapy (ART), scientists at the National Institutes of Health report in ...

Antibody suppresses HIV in infected individuals

November 10, 2016
The administration of VRC01, a potent and broadly neutralizing HIV-specific antibody, is safe, is well-tolerated, generated high plasma concentrations and modestly delayed the return of HIV viral rebound in HIV-1 infected ...

Early antiretroviral therapy dramatically reduces HIV DNA set point

August 1, 2016
A team of researchers, led by Drs. Merlin Robb and Jintanat Ananworanich of the U.S. Military HIV Research Program (MHRP) at the Walter Reed Army Institute of Research, has found that when antiretroviral therapy (ART) is ...

New study provides clues to early T cell immune responses in acute HIV infection

February 15, 2017
A new study has shown that potent HIV-specific CD8+ T cells that are able to kill HIV-producing cells and reduce the seeding of the HIV reservoir are only detected at peak viremia in acute HIV infection. Findings from the ...

Scientists identify potent antibody that neutralizes nearly all HIV strains

November 15, 2016
Scientists from the National Institutes of Health have identified an antibody from an HIV-infected person that potently neutralized 98 percent of HIV isolates tested, including 16 of 20 strains resistant to other antibodies ...

Scientists boost potential of passive immunization against HIV

August 13, 2014
Scientists are pursuing injections or intravenous infusions of broadly neutralizing HIV antibodies (bNAbs) as a strategy for preventing HIV infection. This technique, called passive immunization, has been shown to protect ...

Recommended for you

HIV exports viral protein in cellular packages

February 15, 2018
HIV may be able to affect cells it can't directly infect by packaging a key protein within the host's cellular mail and sending it out into the body, according to a new study out of a University of North Carolina Lineberger ...

Can gene therapy be harnessed to fight the AIDS virus?

February 13, 2018
For more than a decade, the strongest AIDS drugs could not fully control Matt Chappell's HIV infection. Now his body controls it by itself, and researchers are trying to perfect the gene editing that made this possible.

Big data methods applied to the fitness landscape of the HIV envelope protein

February 7, 2018
Despite significant advances in medicine, there is still no effective vaccine for the human immunodeficiency virus (HIV), although recent hope has emerged through the discovery of antibodies capable of neutralizing diverse ...

Scientists report big improvements in HIV vaccine production

February 5, 2018
Research on HIV over the past decade has led to many promising ideas for vaccines to prevent infection by the AIDS virus, but very few candidate vaccines have been tested in clinical trials. One reason for this is the technical ...

Microbiome research refines HIV risk for women

January 25, 2018
Drawing from data collected for years by AIDS researchers in six African nations, scientists have pinpointed seven bacterial species whose presence in high concentrations may significantly increase the risk of HIV infection ...

Researchers find latent HIV reservoirs inherently resistant to elimination by CD8+ T-cells

January 22, 2018
The latest "kick-and-kill" research to eliminate the HIV virus uncovered a potential obstacle in finding a cure. A recent study by researchers at the George Washington University (GW) found that latent HIV reservoirs show ...

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.