|Descriptive Information Fields|
|Brief Title †||Safety and Efficacy of a Three-Dose Regimen of an Adenoviral HIV Vaccine (MRKAd5 HIV-1 Gag/Pol/Nef) in HIV Uninfected South African Adults|
|Official Title †||A Multicenter Double-Blind Randomized Placebo-Controlled Phase IIB Test-of-Concept Study to Evaluate the Safety and Efficacy of a Three-Dose Regimen of the Clade B-Based Merck Adenovirus Serotype 5 HIV-1 Gag/Pol/Nef Vaccine in HIV-1 Uninfected Adults in South Africa|
The purpose of this study is to determine the safety, efficacy, and tolerability of a three-dose regimen of an adenovirus-based HIV-1 vaccine in healthy South African adults.
The HIV epidemic is a major global health challenge. The Joint United Nations Program on HIV/AIDS (UNAIDS) reported that in 2004, 3 million people worldwide died of AIDS and an estimated 5 million people acquired HIV. Studies in animal models and observational data from humans suggest that cell-mediated immune responses may be key to controlling HIV infection. MRKAd5 HIV-1 gag/pol/nef, a clade B-based adenovirus serotype 5 HIV-1 vaccine, has been shown to elicit T-cell mediated immune responses. The vaccine appears to be safe and generally well tolerated in previous Phase 1 and 2 studies in HIV-uninfected people. The purpose of this study is to evaluate the safety and efficacy of the MRKAd5 HIV-1 gag/pol/nef vaccine in HIV-uninfected participants from South Africa, where clade C is predominant. The study will address whether a clade B-based vaccine designed to elicit T-cellular immunity will demonstrate efficacy in reducing acquisition of infection, or reducing HIV viral load in persons who become infected in a non-clade B region.
This study will last about 42 months for HIV-uninfected participants and 18 months for those who become HIV infected. Participants will be randomly assigned to receive 3 doses of either vaccine or placebo. All participants will receive their injections at study entry and at Months 1 and 6. Participants will be asked to complete a post-vaccination symptom log for the 3 days following each vaccination to monitor body temperature and symptoms known to be associated with the vaccine. At all study visits, participants will be asked about any adverse events they may have experienced. There will be at least 14 study visits over the first 4 years of the study. A physical exam, medication history, risk reduction counseling, and blood collection will occur at every visit. Participants will be asked to complete a social impact questionnaire at Weeks 12, 78, and 208; an outside testing and belief questionnaire at Weeks 30, 78, 130, 182, and 208; and a circumcision status assessment at Week 208. Participants will undergo HIV testing to check their HIV status approximately every 3 months.
Participants who become HIV infected during the study will have eight study visits at Weeks 4, 8, 12, 16, 20, 26, 52, and 78 post-diagnosis. A physical exam, risk reduction counseling, blood and urine collection, and a pregnancy test will occur at all visits. Genital secretion collection may also occur at some visits. Participants who become HIV infected and need to begin anti-HIV therapy will be discontinued from this study, but encouraged to enroll in the study HVTN 802.
As of September 17, 2007 enrollment and vaccinations for this study were suspended. Participants already enrolled have been asked to continue attending follow-up visits with this study.
|Study Phase||Phase II|
|Study Type †||Interventional|
|Study Design †||Prevention, Randomized, Open Label, Placebo Control, Parallel Assignment, Safety/Efficacy Study|
|Primary Outcome Measure †||Acquisition of HIV-1 infection [ Time Frame: Throughout study ] [ Designated as safety issue: Yes ]
Viral load set point (HIV-1 RNA) in study participants who become HIV infected [ Time Frame: At approximately 3 months postdiagnosis ] [ Designated as safety issue: No ]
|Secondary Outcome Measure †||Acquisition of HIV-1 infection among participants with baseline Ad5 neutralizing antibody titers of 200 or less [ Time Frame: Throughout study ] [ Designated as safety issue: Yes ]
Viral load setpoint in such study participants [ Time Frame: Throughout study ] [ Designated as safety issue: No ]
Durability of effect of vaccine on suppression of HIV-1 viral RNA and preservation of CD4 counts [ Time Frame: At 18 months after diagnosis of HIV infection ] [ Designated as safety issue: No ]
One time questionnaire evaluating impact of discontinuation of vaccination on participants [ Time Frame: After vaccination discontinuation ] [ Designated as safety issue: No ]
|Condition †||HIV Infections|
|Intervention †||Biological: MRKAd5 HIV-1 gag/pol/nef
|MEDLINE PMIDs||14746526, 11797011|
|Links||Click here for more information on preventive HIV vaccines
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|Recruitment Information Fields|
|Recruitment Status †||Suspended|
|Start Date †||January 2007|
|Completion Date||October 2011|
|Eligibility Criteria †||
As of 9/19/07, clinical research sites were notified that HVTN 503 has been suspended; therefore, enrollment is discontinued and all participants will be unblinded and encouraged to continue follow-up visits.
|Ages||18 Years to 35 Years|
|Accepts Healthy Volunteers||Yes|
|Location Countries †||South Africa|
|Administrative Information Fields|
|NCT ID †||NCT00413725|
|Organization ID||HVTN 503|
|Secondary IDs ††|
|Study Sponsor †||National Institute of Allergy and Infectious Diseases (NIAID)|
|Collaborators ††||HIV Vaccine Trials Network|
|Information Provided By||National Institute of Allergy and Infectious Diseases (NIAID)|
|Verification Date||May 2008|
|First Received Date †||December 18, 2006|
|Last Updated Date||May 16, 2008|