Thai Phase III HIV Vaccine Trial
In March 2008, GSID amended its Materials Transfer and License Agreement with VaxGen, Inc. to obtain the rights and physical possession of the manufacturing materials and data associated with AIDSVAX
® B/B and B/E, the two HIV/AIDS vaccines tested by VaxGen in Phase III clinical trials between 1998 and 2003. The original agreement with VaxGen initially included the rights to only the clinical data and specimens related to the VAX003 and VAX004 clinical trials. Along with the remaining intellectual property related to the AIDSVAX vaccines, GSID was also assigned the license and supply agreement VaxGen had with Genentech, Inc. and assumed the manufacturing sponsorship of AIDSVAX B/E which is currently being tested as a component of a prime boost regimen in Thailand.
The RV144 study is sponsored by the United States Surgeon General via the U.S. Army Medical Material Development Activity and is financed by the Division of AIDS, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH) and the US. Army Medical Research and Materiel Command, Department of Defense. RV 144 is designed to determine if the prime boost combination of ALVAC-HIV vCP1512 and AIDSVAX B/E prevents HIV infection in healthy adult volunteers and/or reduces plasma viremia and CD4+ T cells on those who become infected.
RV144 is a Phase III clinical trial consisting of 16,000 non-infected adult volunteers from two provinces, Rayong and Chon Buri, both on the coast of Central Thailand. The trial is community-based, randomized, multi-center, double-blind and placebo-controlled. Volunteers are between 18 and 30 years of age and are primarily heterosexual, non-injection-drug-using and at low risk of infection.
Enrollment began in 2003 and concluded in December 2005. The vaccination phase of the trial was completed in July 2006. Volunteers received immunizations as follows: four immunizations with ALVAC-HIV vCP1521, “the prime” at 0, 1, 3 and 6 months and two immunizations with AIDSVAX B/E, “the boost,” at 3 and 6 months or placebo. Follow-up is for three years following immunization. During the July 16, 2008 data safety and monitoring board (DSMB) meeting, the board reviewed the trial data for statistical futility and recommended that the trial continue. In addition, no safety concerns associated with the vaccines have been reported since the inception of the trial.
The first co-primary endpoint is prevention of HIV infection. A second co-primary endpoint is very important as well: the effect of immunization on plasma viremia in those who become infected. The study is also assessing risk behavior and impact of the trial on the community. Safety is being closely monitored throughout the trial. This information will be helpful in planning further HIV vaccine clinical trials. The DSMB also reported at its last review that there continues to be no concerns with the safety of the vaccines.
Because RV144 is designed to examine plasma viremia soon after infection, trial collaborators have undertaken a second study, RV152, to follow infected individuals over a longer period of time. The results of this study will help to establish the durability of the vaccine effect, if any, on viral load.
In September 2009, GSID, along with several of its collaborators, announced in their respective press releases that the prime-boost combination had been shown to be safe and modestly effective in preventing HIV infection. In October 2009, detailed results from the Thai Phase III HIV vaccine clinical trial were presented at the AIDS Vaccine 2009 Conference in Paris, France and published online in
The New England Journal of Medicine.
- The New England Journal of Medicine article co-authored by Dr. Donald Francis is available here.
- GSID RV144 results press release is available here.
