All other unsolicited AEs were recorded for 30 days post-vaccination. Severity of AEs was assessed using the National buy PD0325901 Institute of Allergy and Infectious Diseases Division of AIDS (DAIDS) AE grading system [10]. Serious adverse events (SAEs) and the following pre-defined HIV-1-related AEs were assessed throughout the study period: ≥25% reduction in CD4+ T-cell count from baseline; detectable viral load (≥50 copies/ml HIV-1 RNA) in ART-experienced subjects or ≥0.5 log increase in viral load in ART-naïve subjects; change or initiation of ART; and abnormal biochemistry and/or haematology (defined as ≥1 on the DAIDS scale). All solicited

local AEs were considered causally related to vaccination. The potential relationship of all other AEs to vaccination was assessed

by the investigator. Safety data were reviewed by an independent data monitoring committee. HIV-1 viral load was tested with the Roche COBAS® Amplicor HIV-1 Monitor Test v1.5 in ART-experienced subjects and the Roche COBAS® AmpliPrep/COBAS® TaqMan® HIV-1 Test v1.0 in ART-naïve subjects. CD4+ T-cell counts were initially performed using the BD Multitest™ IMK kit (a four-colour assay) (BD Biosciences) and read using a BD FACSCalibur™ flow cytometer. During the study, the method was upgraded to use the BD Multitest™ 6-colour TBNK reagent and the BD FACSCanto™ II system after an extensive validation process. GDC-0199 cost HIV-1-specific CD4+

and CD8+ T-cell responses were evaluated by intracellular cytokine staining (ICS) following in vitro stimulation with p17, p24, RT and Nef peptide pools to assess the expression of interleukin-2 (IL-2), interferon-γ (IFN-γ), tumour necrosis factor-α (TNF-α) and CD40-ligand (CD40L) using peripheral blood mononuclear cells (PBMCs) isolated from venous blood [8]. HIV-1-specific CD4+ T-cell responses were expressed as the frequency of CD40L+CD4+ T-cells expressing at least IL-2, the cytokine co-expression profile and the percentage of Resminostat responders after in vitro stimulation to each individual antigen and to at least 1, 2, 3 or 4 antigens. This was a pre-defined endpoint based on results of a previous study of F4/AS01 in healthy HIV-1-seronegative volunteers, in which almost all vaccine-induced CD4+ T-cells were found to express at least CD40L and IL2 [8]. If cytokine secretion was undetectable pre-vaccination, a subject was considered a responder if the proportion of CD40L+CD4+ T-cells expressing at least IL-2 was ≥0.03% (assay cut-off). In subjects with detectable cytokine secretion pre-vaccination, response was defined as a greater than 2-fold increase in CD40L+CD4+ T-cells expressing at least IL-2 from baseline. HIV-1-specific CD8+ T-cell responses were expressed as the frequency of CD8+ T-cells expressing at least 1 cytokine (IL-2, TNF-α, or IFN-γ).