A Study of Safety, Tolerability, and Immunogenicity of the MRKAd5 Gag/Pol/Nef Vaccine in Healthy Adults (V520-016)

Merck Sharp & Dohme LLC317 enrolled

Overview

The goal of this study is to understand the safety, tolerability and immunogenicity of the Merck Trivalent Adenovirus Serotype 5 HIV-1 gag/pol/nef Vaccine (MRKAd 5 HIV-1 gag/pol/nef) vaccine in healthy human volunteers compared to placebo. The study will also evaluate a number of dose levels and the necessity for and timing of booster injections.

The study will proceed in four stages. Following stages I, II and III, all subjects will have the Postdose 1 (PD1) clinical and laboratory safety data reviewed by the Safety Evaluation Committee (SEC). If these data are acceptable, the next stage will be initiated. * In Stage I, participants will be randomized to receive 3 doses of the 3x10\^9vp/dose level Trivalent vaccine or placebo. * In Stage II, participants will be randomized to receive 2 or 3 doses of the 3x10\^10vp/dose level Trivalent vaccine or placebo. * In Stage III, participants will be randomized to receive 3 doses of the Trivalent vaccine with titers of 1x10\^11vp/dose, 3x10\^6vp/dose, 3x10\^7vp/dose, or 3x10\^8vp/dose or placebo. * In Stage IV, participants will be randomized to all treatment groups. In addition, some participants will be randomized to an MRKAd 5 HIV-1 gag Monovalent vaccine. In this stage, participants will be pre-stratified by baseline Ad5 titers (=\<200, and \>200), to ensure an even distribution of participants with high and low Ad5 titers across the various treatment groups.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

DOUBLE

Enrollment

317

Conditions

HIV-1 HIV Infections

Interventions

Comparator: Placebo to the MRKAd5 HIV-1 gag/pol/nef vaccineOTHER

Placebo to the MRKAd5 HIV-1 gag/pol/nef vaccine.

Monovalent MRKAd5 HIV-1 gag vaccine (1x10^9 vp/dose)BIOLOGICAL

Monovalent MRKAd5 HIV-1 gag vaccine (1x10\^9 vp/dose)

Trivalent MRKAd5 HIV-1 gag/pol/nef vaccine (3x10^6 vp/dose)BIOLOGICAL

Trivalent MRKAd5 HIV-1 gag/pol/nef vaccine (3x10\^6 vp/dose)

Eligibility

Sex: ALLMin age: 18 YearsMax age: 45 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Subjects 18 Years to 45 Years in Stages I-III and 18 Years to 50 Years in Stage IV. * Subject is in good general health * Subjects of reproductive potential agree to use acceptable method of birth control through study * Subject tests negative for Hepatitis B, Hepatitis C, and HIV Exclusion Criteria: * Subject has a recent history of fever at time of vaccination * Subject has received immune globulin or blood product 3 months prior to injection * Subject has been vaccinated with live virus vaccine 30 days prior to receipt of first dose * Subject has been vaccinated with inactivated vaccine with 14 days prior to receipt of first dose * Subject has a chronic medical condition that is considered progressive * Subject has history of malignancy * Subject weighs less than 105 lb. * Female subject is pregnant or breast feeding, Male subject is planning to impregnate during the first year of study * Subject has contraindication to intramuscular injection * Subject has a tattoo on the deltoid region of the arm or the injection of Depo-Provera * Subject is unlikely or unwilling to adhere to lower risk sex practices during the course of the study

Outcomes

Primary Outcomes

Number of Participants With Adverse Experiences

Adverse experiences (AE) collected include serious and non serious systemic AEs, and injection-site AEs. Systemic and Laboratory AEs include any unfavorable \& unintended change in the structure, function, or chemistry of the body. Injection-site AEs include any swelling, redness, pain or tenderness at the injection site. All injection site AEs were collected up to 5 days after any vaccine dose.

Time frame: up to 260 weeks after first vaccination

Number of Participants With Laboratory Adverse Experiences

Laboratory AEs were based on a grading system considering the severity of abnormal laboratory values in participants and reflect any unfavorable and unintentional change in function, or chemistry of the body. All laboratory AEs were collected up to 29 days after any vaccine dose.

Time frame: up to 260 weeks after first vaccination

Immune Response by Levels of Unfractionated Gag, Pol, and Nef-specific IFN-gamma Following a 3-dose Vaccine Regimen

Time frame: 4 weeks after booster injection

Immune Response by Levels of Unfractionated Gag, Pol, and Nef-specific IFN-gamma Following a 2-dose Vaccine Regimen

Participants expressing HIV antigens (gag, pol and nef) secrete antigen specific interferon-gamma (IFN-gamma). Levels of unfractionated gag, pol, and nef-specific IFN-gamma were to be measured using an Enzyme Linked Immunospot Assay (ELISPOT), which measures spot forming cells per 10\^6 peripheral blood mononuclear cells (SFC per million PBMCs). No immunogenicity analyses were performed because the results from a previous study, V520-023 (NCT00095576), which used the same vaccine as the one used in this study (NCT00849680) proved it was not efficacious.

Time frame: 4 weeks after booster injection

Data from ClinicalTrials.gov

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