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HIV InfectionsPhase 2NCT00413725

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

A Phase 2 study testing MRKAd5 HIV-1 gag/pol/nef in people with HIV Infections, run by National Institute of Allergy and Infectious Diseases (NIAID) at 5 sites in South Africa.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

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. Read more about this study

Who is it for?
Ages 18 to 35 yearsHealthy volunteers can take part
Conditions the study is for
HIV Infections
What is being tested?
MRKAd5 HIV-1 gag/pol/nef
Type of treatment
Vaccines
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
801 participants
Where
5 sitesSouth Africa
Study dates
Jan 2007to Aug 2012
Phase
Phase 2
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 35 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • HIV-1 and -2 negative
  • Good general health
  • ALT less than 2.6 times the upper limit of normal (ULN)
  • Sexually active within the 6 months prior to study entry
  • Have access to a participating HIV Vaccine Trials Unit (HVTU) and are willing to be followed during the study
  • Demonstrate understanding of the study
  • Willing to receive HIV test results
  • Female participants must be willing to use acceptable forms of contraception, or not be of reproductive potential. More information about this criterion can be found in the protocol.

Who cannot join

  • Adenovirus 5 titer greater than 200, once enrollment of participants in this stratum has been completed
  • HIV vaccines in prior HIV trial. Participants who can provide documentation that they received a placebo in a prior HIV trial may be eligible.
  • Immunosuppressive medications within 168 days prior to first study vaccination. Participants who have used corticosteroid nasal sprays for allergic rhinitis or topical corticosteroids for mild, uncomplicated dermatitis are not excluded.
  • Blood products within 90 days prior to first study vaccination
  • Immunoglobulin within 90 days prior to first study vaccination
  • Live attenuated vaccines within 30 days prior to first study vaccination
Show all 19Show fewer
  • Investigational research agents within 30 days prior to first study vaccination
  • Medically indicated subunit or killed vaccines within 5 days prior to first study vaccination OR scheduled to receive such vaccines within 14 days after first study vaccination
  • Allergy treatment with antigen injections within 30 days prior to first study vaccination
  • Clinically significant medical condition, abnormal physical exam findings, abnormal laboratory results, or past medical history that may affect current health. More information about this criterion can be found in the protocol.
  • Any medical, psychiatric, or job-related responsibility that would interfere with the study. More information about this criterion can be found in the protocol.
  • Any concern that, in the opinion of the investigator, may interfere with a participant's completion of the post-vaccination symptom log
  • History of anaphylaxis or allergy to any of the vaccine's components
  • Autoimmune disease
  • Immunodeficiency
  • Bleeding disorder
  • Cancer
  • Seizure disorder
  • Pregnancy or breastfeeding

Trial locations and contacts

5 sites in 1 country.

5 sites in 1 country

South Africa5 sites
  • Emavundleni CRS

    Cape Town, Western Cape, 7750

  • eThekwini CRS

    Durban, KwaZulu-Natal, 4001

  • Soweto HVTN CRS

    Johannesburg, Gauteng, 1862

  • CAPRISA Aurum CRS

    Klerksdorp, 2571

  • MedCRU CRS

    Pretoria, Gauteng, 0204

Other trials in South Africa

About this study

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.

Read the detailed description

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; for those who become HIV infected, visits continue for 18 months after diagnosis. 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.

Participants who were not diagnosed with HIV infection during their participation in the study will be eligible to enroll in a substudy. The purpose of the substudy is to expand HIV testing and to gather data on behavioral risk factors for HIV infection among participants in the original study. Participants in the substudy will attend a study visit, which will include a physical examination, HIV risk reduction counseling, blood collection, and a behavioral risk questionnaire. Some participants may have an HIV test as part of this visit; these participants will attend a second study visit 2 weeks later to receive their HIV test results. Upon completion of the substudy, researchers will contact participants to provide further information about the substudy results.

Conditions
HIV Infections
Being tested
MRKAd5 HIV-1 gag/pol/nef, Placebo
Keywords
HIV Seronegativity, HIV Preventive Vaccine, Adenovirus
Medical subject headings
HIV Infections, Adenoviridae Infections

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • MRKAd5 HIV-1 gag/pol/nefBiological

    Experimental Clade-B based Adenovirus serotype 5 HIV-1 gag/pol/nef vaccine

  • PlaceboOther

    Placebo

Study groups in NCT00413725
Study groupRoleWhat they receive
1ExperimentalThree doses of MRKAd5 HIV-1 gag/pol/nef vaccine
Receives: Biological: MRKAd5 HIV-1 gag/pol/nef
2Placebo comparatorPlacebo
Receives: Other: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Acquisition of HIV-1 infection

    Measured: Throughout study

  2. Viral load set point (HIV-1 RNA) in study participants who become HIV infected

    Measured: At approximately 3 months postdiagnosis

Secondary outcomes (4)
  1. Acquisition of HIV-1 infection among participants with baseline Ad5 neutralizing antibody titers of 200 or less

    Measured: Throughout study

  2. Viral load setpoint in such study participants

    Measured: Throughout study

  3. Durability of effect of vaccine on suppression of HIV-1 viral RNA and preservation of CD4 counts

    Measured: At 18 months after diagnosis of HIV infection

  4. One time questionnaire evaluating impact of discontinuation of vaccination on participants

    Measured: After vaccination discontinuation

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted20 Dec 2006 (estimated)
  2. Study startJan 2007
  3. Primary completionAug 2012
  4. Study completionAug 2012

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
801 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT00413725
Sponsor's protocol ID
HVTN 503 (Phambili)
Other IDs
10392, HVTN 503
Status last verified
Oct 2021
First submitted
18 Dec 2006
Last updated
15 Oct 2021
Results posted
No

Publications

  • Morgan C, Bailer R, Metch B, Koup R, Paranjape RS, Vardas E, Pape JW, Figueroa JP, Barroso, P, Kalichman A, Jaspan H, Lama J, Jack N, Russell N. International seroprevalence of neutralizing antibodies against adenovirus serotypes 5 and 35. AIDS Vaccine 2005. Montreal, September 7, 2005.

  • Shiver JW, Emini EA. Recent advances in the development of HIV-1 vaccines using replication-incompetent adenovirus vectors. Annu Rev Med. 2004;55:355-72. doi: 10.1146/annurev.med.55.091902.104344.

    PubMed 14746526
  • Shiver JW, Fu TM, Chen L, Casimiro DR, Davies ME, Evans RK, Zhang ZQ, Simon AJ, Trigona WL, Dubey SA, Huang L, Harris VA, Long RS, Liang X, Handt L, Schleif WA, Zhu L, Freed DC, Persaud NV, Guan L, Punt KS, Tang A, Chen M, Wilson KA, Collins KB, Heidecker GJ, Fernandez VR, Perry HC, Joyce JG, Grimm KM, Cook JC, Keller PM, Kresock DS, Mach H, Troutman RD, Isopi LA, Williams DM, Xu Z, Bohannon KE, Volkin DB, Montefiori DC, Miura A, Krivulka GR, Lifton MA, Kuroda MJ, Schmitz JE, Letvin NL, Caulfield MJ, Bett AJ, Youil R, Kaslow DC, Emini EA. Replication-incompetent adenoviral vaccine vector elicits effective anti-immunodeficiency-virus immunity. Nature. 2002 Jan 17;415(6869):331-5. doi: 10.1038/415331a.

    PubMed 11797011
  • Gray GE, Allen M, Moodie Z, Churchyard G, Bekker LG, Nchabeleng M, Mlisana K, Metch B, de Bruyn G, Latka MH, Roux S, Mathebula M, Naicker N, Ducar C, Carter DK, Puren A, Eaton N, McElrath MJ, Robertson M, Corey L, Kublin JG; HVTN 503/Phambili study team. Safety and efficacy of the HVTN 503/Phambili study of a clade-B-based HIV-1 vaccine in South Africa: a double-blind, randomised, placebo-controlled test-of-concept phase 2b study. Lancet Infect Dis. 2011 Jul;11(7):507-15. doi: 10.1016/S1473-3099(11)70098-6. Epub 2011 May 11.

    PubMed 21570355
  • Leitman EM, Hurst J, Mori M, Kublin J, Ndung'u T, Walker BD, Carlson J, Gray GE, Matthews PC, Frahm N, Goulder PJ. Lower Viral Loads and Slower CD4+ T-Cell Count Decline in MRKAd5 HIV-1 Vaccinees Expressing Disease-Susceptible HLA-B*58:02. J Infect Dis. 2016 Aug 1;214(3):379-89. doi: 10.1093/infdis/jiw093. Epub 2016 Mar 6.

    PubMed 26951820
  • Moodie Z, Metch B, Bekker LG, Churchyard G, Nchabeleng M, Mlisana K, Laher F, Roux S, Mngadi K, Innes C, Mathebula M, Allen M, Bentley C, Gilbert PB, Robertson M, Kublin J, Corey L, Gray GE. Continued Follow-Up of Phambili Phase 2b Randomized HIV-1 Vaccine Trial Participants Supports Increased HIV-1 Acquisition among Vaccinated Men. PLoS One. 2015 Sep 14;10(9):e0137666. doi: 10.1371/journal.pone.0137666. eCollection 2015.

    PubMed 26368824
  • Gray GE, Moodie Z, Metch B, Gilbert PB, Bekker LG, Churchyard G, Nchabeleng M, Mlisana K, Laher F, Roux S, Mngadi K, Innes C, Mathebula M, Allen M, McElrath MJ, Robertson M, Kublin J, Corey L; HVTN 503/Phambili study team. Recombinant adenovirus type 5 HIV gag/pol/nef vaccine in South Africa: unblinded, long-term follow-up of the phase 2b HVTN 503/Phambili study. Lancet Infect Dis. 2014 May;14(5):388-96. doi: 10.1016/S1473-3099(14)70020-9. Epub 2014 Feb 20.

    PubMed 24560541
  • Latka MH, Fielding K, Gray GE, Bekker LG, Nchabeleng M, Mlisana K, Nielson T, Roux S, Mkhize B, Mathebula M, Naicker N, de Bruyn G, Kublin J, Churchyard GJ; HVTN 503 Phambili study team. Pregnancy incidence and correlates during the HVTN 503 Phambili HIV vaccine trial conducted among South African women. PLoS One. 2012;7(4):e31387. doi: 10.1371/journal.pone.0031387. Epub 2012 Apr 19.

    PubMed 22532824

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing MRKAd5 HIV-1 gag/pol/nef in people with HIV Infections, run by National Institute of Allergy and Infectious Diseases (NIAID) at 5 sites in South Africa.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 8 inclusion and 19 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 15 Oct 2021. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 5 sites in South Africa. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Acquisition of HIV-1 infection (time frame: Throughout study). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT00413725, which also lists 8 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Oct 2021.

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