Randomized, Placebo Controlled, Partially Blinded Phase II Study to Evaluate Safety, Immunogenicity, and Prevention of Infection with Mycobacterium tuberculosis of AERAS-404 and BCG Revaccination in Healthy Adolescents
This Phase II, randomized, 3-arm, placebo controlled, partially blinded, clinical trial will be conducted in 990 healthy, HIV-uninfected, QFT-GIT negative, previously BCG vaccinated adolescents. The trial will be conducted at the South African Tuberculosis Vaccine Initiative (SATVI) site in the Western Cape region of South Africa, where epidemiological studies involving thousands of adolescents have been conducted over the last decade to characterize rates of Mtb infection and active TB disease in this age group. Subjects will be enrolled in two sequential cohorts and within each cohort subjects will be randomized in a 1:1:1 ratio to receive either AERAS-404 or saline placebo on Days 0 and 56, or BCG Vaccine SSI on Day 0. The first 90 subjects (30 from each arm) will form the Safety \& Immunogenicity Cohort and will be subject to more intensive collection of safety data, with data reviewed by the Data Monitoring Committee (DMC), principal investigator and local medical monitor. Selected immunogenicity assays, including whole blood intracellular cytokine staining (ICS), will also be performed in this cohort. The remaining 900 subjects will be enrolled into the Correlates Cohort. All 990 subjects in the study will be evaluated for safety and biomarker outcomes, and for prevention of Mtb infection. The primary Mtb infection endpoint will be QFT-GIT conversion from a negative to positive test, using the manufacturer's recommended threshold of 0.35 IU/mL, at any time-point after Day 84 and through end of follow-up for the primary endpoint. The 84-day 'wash-out' period is stipulated in order to exclude subjects who may have already been Mtb infected, but not yet converted their QFT-GIT test at screening, thus subjects who convert their QFT-GIT at Day 84 will not be included in the analyses of prevention of Mtb infection.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
QUADRUPLE
Enrollment
989
The H4 antigen is a fusion protein created from two Mtb antigens: antigen Ag85B and TB10.4. Ag85B is also referred to as α-antigen and is a 30-kDa mycolyl transferase protein. TB10.4 is one of three members of the very similar ESAT-6 group of proteins found in Mtb culture supernatants. TB10.4 induces broad immune responses in T cells isolated from TB subjects compared to BCG-vaccinated donors and unvaccinated donors. IC31 is a combination of a leucine-rich peptide named KLK \& a synthetic oligonucleotide named ODN1a. The optimal molar ratio of KLK to ODN1a in mice is 25:1. AERAS-404 \& saline placebo trial arms will be double-blinded since BCG causes a recognizable local injection site reaction, the BCG revaccination trial arm will be unblinded.
Saline
South African Tuberculosis Vaccine Initiative , Project Office, Brewelskloof Hospital , Harlem Street, Worcester
Cape Town, Western Cape, South Africa
Desmond Tutu HIV Foundation (DTHF)
Nyanga, South Africa
Safety Profile of H4:IC31 and BCG Revaccination in HIV-uninfected, Remotely BCG Vaccinated Adolescents.
Number of unsolicited and solicited adverse events recorded post vaccination. Unsolicited adverse events: 28 days post each vaccination Solicited adverse events: 7 days post each vaccination (with diary cards used for 7 days after each vaccination for Safety and Immunogenicity Cohort only) Solicited and unsolicited injection site reaction adverse events: BCG Group - 84 days post vaccination; H4:IC31/Placebo Groups - 28 days post each vaccination Serious adverse events, adverse events of special interest, and SUSARs: Entire study period, with a minimum of 6 months following the last dose of study vaccine
Time frame: Study day 7 thru 6 months after last vaccination
Number of Participants Testing Positive for Mtb at Day 84
Rates of conversion to Mtb-positive measured by QuantiFERON-TB Gold In-tube (QFT-GIT) assay. The primary evaluation of Mtb infection was QFT-GIT conversion from a negative to positive test, using the manufacturer's recommended threshold of ≥0.35 IU/mL, at any time point after Day 84 and through end of follow-up for the primary endpoint. All participants with primary QFT-GIT conversion were followed for an additional 6 months post-conversion to ascertain the sustained QFT-GIT conversion and QFT-GIT reversion endpoints. Participants with an initial QFT-GIT conversion at Month 6 or 12 were asked to return for a final QFT-GIT evaluation and assessment for TB signs and symptoms at least 24 months after their initial vaccination. * H4:IC31 compared to placebo * BCG revaccination compared to placebo
Time frame: Study day 84 through 6 months post-conversion
Rates of Sustained Conversion to Mtb-positive
Rates of sustained conversion to Mtb-positive as measured by QFT-GIT assay. * H4:IC31 compared to placebo * BCG revaccination compared to placebo
Time frame: 6 months after initial conversion
Percentage of Participants With Immune Response to Vaccine in HIV-uninfected, Remotely BCG-vaccinated Adolescents: o H4:IC31 o BCG Revaccination
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
BCG SSI Vaccine is registered in South Africa for prevention of TB in children and adults. BCG, an attenuated, live culture of the Bacillus Calmette-Guérin, was originally attenuated between 1906 and 1919 by serial passage of an M. bovis strain. The manufacturer Statens Serum Institut (SSI) in Copenhagen, Denmark derives this vaccine from the Danish BCG strain 1331. BCG SSI is supplied by the manufacturer in amber 10-dose vials containing 0.75 mg lyophilized SSI BCG. The BCG revaccination trial arm will be unblinded (open label).
A 13 color intracellular cytokine staining assay (ICS) was performed on peripheral blood mononuclear cells (PBMC) to assess CD4+ T cells that expressed IFN-γ, TNF, IL-2, IL-17, IL-22, CD107a, and/or CD154 alone or in combination in response to stimulation with peptide pools representing the entire amino acid sequence of the TB mycobacterial antigens Ag85B and TB10.4, and BCG antigens. Responders were IFN-gamma and/or IL-2 positive. An intracellular cytokine assay was performed on whole blood (WB) to measure the frequencies and patterns of CD4+ T cells expressing Th1 and Th17 cytokines following stimulation of whole blood with peptide pools representing the entire amino acid sequence of the TB mycobacterial antigens Ag85B and TB10.4, as well as viable BCG from the vaccine vial. Responders were IFN-gamma, IL-2, TNF, IL-17, and/or IL-22 positive.
Time frame: Study day 70