Safety and immunogenicity of CD40.HIVRI.Env, a dendritic cell-based HIV vaccine, in healthy HIV-uninfected adults: a first-in-human randomized, placebo-controlled, dose-escalation study (ANRS VRI06)

Abstract

Background: Current HIV prophylactic vaccines evaluate HIV Env as purified proteins. CD40.HIVRI.Env is an innovative antigen delivery targeting gp140 Env from HIV Clade C 96ZM651 to CD40-expressing antigen-presenting cells, thus harnessing the intrinsic immune-stimulant properties. DNA-HIV-PT123 vaccine encodes 96ZM651 gp140/Gag and 97CN54 Pol/Nef.

Methods: Seventy-two HIV-negative volunteers were enrolled between 05/2021 and 10/2022 in a phase 1 placebo-controlled trial conducted in France and Switzerland (N° EudraCT: 2020-001814-40; NCT04842682). Volunteers were randomized (5:1 active versus placebo) in groups receiving either 0.3, 1.0, or 3.0 mg CD40.HIVRI.Env (Hiltonol® adjuvanted) alone or co-administered with DNA-HIV-PT123 at weeks (W) 0, 4, and 24. Safety and immunogenicity were monitored until W48. The primary safety endpoint was the proportion of participants per dose cohort and randomized arm without any grade 3 or 4 biological (abnormal laboratory values), or clinical local or systemic solicited, or unsolicited adverse events between W0 and W48 considered to be related or possibly related to the investigational products.

Findings: CD40.HIVRI.Env was well tolerated. Env-specific CD4⁺ T-cells (IL-2⁺ or IFN-γ⁺ or TNF⁺) were detected in all vaccinees from W6 to W26 and persisted until W48 without a dose-response signal or an effect of DNA-HIV-PT123 co-administration. At W26, IgG response rates (RR) against autologous and nine heterologous gp120/gp140 were 89-100% across all groups and 56-100% at W48. RR against 96ZM651gp70V1V2 were high (90-100%) at W6 and W26 in all groups. Tier1A MW965.26 neutralizing antibody (nAb) titres were detectable in 50-100% of vaccinated individuals at W26, with a dose-response signal, while one volunteer developed nAbs against five Tier2 viruses.

Interpretation: CD40.HIVRI.Env alone or administered with DNA-HIV-PT123 was safe and induced early, and sustained anti-Env cellular and V1V2 IgG responses, identified as correlates of protection in the RV144 trial. CD40 targeting Env-based vaccines may be instrumental for inducing protective vaccine responses in prime-boost strategies.

Funding: ANRS Emerging infectious diseases (ANRS MIE); Vaccine Research Institute (VRI).

Keywords: DNA vaccine; Dendritic cell targeting; First-in-human clinical trial; HIV vaccines; Immunogenicity.

Fig. 1

Overview of the ANRS VRI06 trial design.

Fig. 2

Flowchart diagram of participant enrolment and follow up for the CD40 groups (A) and DNA + CD40 groups (B).

Fig. 3

Adverse events related to vaccination by grade, group, and sequence of injection.

Fig. 4

Env-specific CD4⁺T-cell response. (A) Percentage of CD4⁺ T-cells expressing IL-2 and/or IFN-γ and/or TNF at W6, W26, and W48 for the CD40 groups (in red), DNA + CD40 groups (in blue), and Placebo (in grey). Boxplots with the median, interquartile range (IQR) and 1.5 times IQR. (B) Functional composition of CD4⁺ T-cell responses at W6, W26, and W48 for the CD40 and DNA + CD40 groups. Responses are color-coded according to the combination of cytokines produced. The arcs identify cytokine-producing subsets (IFN-γ, IL-2, and TNF) within the CD4⁺ T-cell population. (C) Percentage of CD4+ (left) and CD8+ (right) T-cells expressing IL-2 and/or IFN-γ and/or TNF at W0 and W6 for the CD40 0.3 mg group (active vaccinees in red, n = 10; and placebo in grey, n = 2) following in vitro stimulation at D0 and re-stimulation at D8 with Env peptide pools (exploratory post-hoc experiment). Each dot represents a participant and the median is shown as a solid line.

Fig. 5

gp120/gp140 antibody response. (A) IgG responses as the background subtracted mean fluorescence intensity (MFI—blank) for CD40 groups (in red), DNA + CD40 groups (in blue), and Placebo (in grey) are described with boxplots against autologous gp140 antigens at W6, W26 and W48. (B) and a heterologous gp120/gp140 panel at W26. Response rates and relevant clades are summarized above each plot. Non-responders, defined by a post-vaccination MFI-blank < antigen/isotype specific MFI-blank threshold based on the 95th percentile of the MFI-blank at W0 or MFI-blank ≤3 × MFI-blank at W0, are shown as triangles. Boxplots are shown with the median, interquartile range (IQR), and 1.5 times the IQR.

Fig. 6

V1V2 antibody response. (A) IgG responses as the background subtracted mean fluorescence intensity (MFI—blank) for CD40 groups (in red), DNA + CD40 groups (in blue), and Placebo (in grey) are described with boxplots against autologous gp70 antigens at W6, W26, and W48. (B) and the same with IgG3. Response rates and relevant clades are summarized above each plot. Non-responders, defined by a post-vaccination MFI-blank < antigen/isotype specific MFI-blank threshold based on the 95th percentile of the MFI-blank at W0 or MFI-blank ≤3 × MFI-blank at W0, are shown as triangles. Boxplots are shown with the median, interquartile range (IQR), and 1.5 times the IQR.

Fig. 7

Neutralizing antibody activity. (A) Neutralizing antibody response as the ID50 for the CD40 groups (in red), DNA + CD40 groups (in blue), and Placebo (in grey) are described with boxplots for Tier1A virus MW965.26. (B) and Tier1A virus SF162 at W26. Response rates and relevant clades are summarized above each plot. Non-responders, defined as those with an ID50 < 60, are shown as triangles. Boxplots are shown with the median, interquartile range (IQR), and 1.5 times the IQR.

Fig. 8

Cross-trial comparison of antibody responses. (A) W26 IgG responses against autologous ENV, (B) heterologous ENV, (C) and autologous V1V2 antigens for the HVTN 096, HVTN 100, HVTN 105, and RV144 trials are shown to compare the ANRS VRI06 results with those of contemporary HIV vaccine trials. All data from other studies were modified by cross-multiplication of dilution factors to the 1:20 dilution factor used in the ANRS VRI06 trial to ensure comparability. (D) The neutralizing antibody response against Tier1A virus MW965.26 at W26 for the HVTN 096, HVTN 100, and HVTN 105 trials is provided to compare the ANRS VRI06 results with those of contemporary HIV vaccine trials. Response rates are summarised below each plot. Boxplots with median, interquartile range (IQR) and 1.5 times IQR.

Fig. 9

Correlations between immune response markers at W26. Multiparametric matrix correlation plot of immune responses between assays at W26 in the CD40 and DNA + CD40 groups (pooled). Spearman's correlation coefficients are shown by colour intensity. For heterologous multiple sequences, the mean response across sequences was used in this analysis. Only statistically significant correlations, after FDR-adjustment for test multiplicity, are shown.