Inducing dose sparing with inactivated polio virus formulated in adjuvant CAF01.

The development of new low cost inactivated polio virus based vaccines (IPV) is a high priority, and will be required to eradicate polio. In addition, such a vaccine constitutes the only realistic polio vaccine in the post-eradication era. One way to reduce the cost of a vaccine is to increase immunogenicity by use of adjuvants. The CAF01 adjuvant has previously been shown to be a safe and potent adjuvant with several antigens, and here we show that in mice IPV formulated with CAF01 induced increased systemic protective immunity measured by binding and neutralization antibody titers in serum. CAF01 also influenced the kinetics of both the cellular and humoral response against IPV to produce a faster, as well as a stronger, response, dominated by IgG2a, IgG2b, and IgG2c isotypes as well as IPV specific T cells secreting IFN-γ/IL-2. Finally, as intestinal immunity is also a priority of polio vaccines, we present a vaccine strategy based on simultaneous priming at an intradermal and an intramuscular site that generate intestinal immune responses against polio virus. Taken together, the IPV-CAF01 formulation constitutes a new promising vaccine against polio with the ability to generate strong humoral and cellular immunity against the polio virus

CAF01 induced dose sparing measured by virus neutralization titers.

<p>Virus neutralization antibody titers from mice (n = 11–12/group) 14 days following the second IM immunization with inactivated polio vaccine (TP) (with or without adjuvant). Neutralizing antibody titers against poliovirus serotypes 1–3 are shown. The individual titers for each mouse are plotted and the bar represents the mean neutralizing antibody titer. SEM of estimated log₂ values are shown, *, p<0.05, **, p<0.01, ***, p<0.001 as indicated in the graph using one-way ANOVA and Tukeys post-test for multiple comparisons. Indicated dosage units in the experiments correspond to Type 1 D-antigen units.</p

CAF01 increase the Antibody binding titers.

<p><b>A</b>. The serum IgG against TP or the individual virus serotypes was measured by indirect ELISA using trivalent IPV or the MPs as the antigen. The Ab titer was measured by the reaction of a series of 10-fold dilution of sera with the antigen. The Ab titration from the sera of 4 mice are shown for the vaccine groups indicated. <b>B</b>. The serum IgG1, IgG2a, IgG2b and IgG2c against TP was measured by indirect ELISA using trivalent IPV as the antigen. (N = 6–8). <b>C</b>. Serum IgG against TP 5 and 8 weeks post the second vaccination in the vaccination groups indicated (N = 6). Indicated dosage units in the experiments correspond to Type 1 D-antigen units. All mice were vaccinated via the IM route with inactivated polio vaccine (TP).</p

IM+ID administration of CAF01 induces intestinal IgA.

<p><b>A</b>. Mice were vaccinated twice at two weeks intervals. Two weeks after the second immunization with the indicated TP vaccines IgA and IgG isotypes was analyzed in fecal samples. The fecal samples were pooled within each experimental group. <b>B</b>. Serum IgG against TP two weeks post vaccination 2. The vaccination groups are indicated (N = 4). <b>C</b>. Virus neutralizing antibody titers against poliovirus serotype 1–3 are shown. The individual titers for each mouse are plotted and the bar represents the mean neutralizing antibody titer. SEM of estimated log₁₀ values from N = 8 mice per group *, p<0.05, **, p<0.01, ***, p<0.001 are indicated in the graph using one-way ANOVA and Tukey's post-test for multiple comparisons. Indicated dosage units in the experiments correspond to Type 1 D-antigen units.</p

Comparing 2 versus 3 vaccinations.

<p>Virus neutralization antibody titers from mice (n = 4/group) 14 days following the second or the third IM immunization with inactivated polio vaccine (TP) (with or without adjuvant). Neutralizing antibody titers against poliovirus serotype 1–3 are shown. The individual titers for each mouse are plotted and the bar represents the mean neutralizing antibody titer. SEM of estimated log₁₀ values from N = 4 mice per group *, p<0.05, **, p<0.01, ***, p<0.001 are indicated in the graph using one-way ANOVA and Tukey's post-test for multiple comparisons. Indicated dosage units in the experiments correspond to Type 1 D-antigen units.</p

CAF01 induction of cellular immunity.

<p><b>A and B</b>. Mice were vaccinated twice at two weeks intervals with IPV (TP) 2DU (white bars), IPV 20DU (grey bars) or IPV 2DU + CAF01 (black bars). Striped bars indicate non-vaccinated mice. At week 2 (A) or week 5 (B) post vaccination 2, PBMCs were stimulated with IPV for 72 hours and secretion of the indicated cytokines was analyzed by MSD. The cytokines are indicated in the figure. Indicated dosage units in the experiments correspond to Type 1 D-antigen units. All mice were vaccinated via the IM route with inactivated polio vaccine (TP).</p

The IPV-CAF01 formulation.

<p><b>A</b>. The Z_avg hydrodynamic diameter of IPV3 (2237 DU/ml), IPV TP (400∶80∶320 DU), CAF01 (2500DDA/500TDB) and IPV (8DU)-CAF01 (2500DDA/500TDB). All data show the average of 3 measurements. <b>B</b>. Analysis of IPV content, as D-unit activity, of the indicated formulations. <b>C</b>. The Zeta potential of IPV, CAF01 and IPV-CAF01 formulations. <b>D</b>. The degree of association between CAF01 and IPV was determined by measuring the IPV content in the pellet or supernatant fraction by DU ELISA. The content of IPV in similar vaccine without CAF01 was also measured (“IPV1-3 content”).</p

Personalized therapy with peptide-based neoantigen vaccine (EVX-01) including a novel adjuvant, CAF®09b, in patients with metastatic melanoma

The majority of neoantigens arise from unique mutations that are not shared between individual patients, making neoantigen-directed immunotherapy a fully personalized treatment approach. Novel technical advances in next-generation sequencing of tumor samples and artificial intelligence (AI) allow fast and systematic prediction of tumor neoantigens. This study investigates feasibility, safety, immunity, and anti-tumor potential of the personalized peptide-based neoantigen vaccine, EVX-01, including the novel CD8(+) T-cell inducing adjuvant, CAF®09b, in patients with metastatic melanoma (NTC03715985). The AI platform PIONEER(TM) was used for identification of tumor-derived neoantigens to be included in a peptide-based personalized therapeutic cancer vaccine. EVX-01 immunotherapy consisted of 6 administrations with 5–10 PIONEER(TM)-predicted neoantigens as synthetic peptides combined with the novel liposome-based Cationic Adjuvant Formulation 09b (CAF®09b) to strengthen T-cell responses. EVX-01 was combined with immune checkpoint inhibitors to augment the activity of EVX-01-induced immune responses. The primary endpoint was safety, exploratory endpoints included feasibility, immunologic and objective responses. This interim analysis reports the results from the first dose-level cohort of five patients. We documented a short vaccine manufacturing time of 48–55 days which enabled the initiation of EVX-01 treatment within 60 days from baseline biopsy. No severe adverse events were observed. EVX-01 elicited long-lasting EVX-01-specific T-cell responses in all patients. Competitive manufacturing time was demonstrated. EVX-01 was shown to be safe and able to elicit immune responses targeting tumor neoantigens with encouraging early indications of a clinical and meaningful antitumor efficacy, warranting further study