Safety and immunogenicity of an adjuvant-free peptide vaccine targeting IL-17A: Phase 1 randomized controlled trial

We investigated whether a peptide vaccine (FPP003) composed of B cell epitope for IL-17A and T cell epitope (AJP001) with innate immune activation could induce the antibody production without adjuvants. The safety and immune response of FPP003 were evaluated in a double-blind trial. Twenty healthy participants received either a low or high dose of FPP003 (n = 8, respectively) or placebo (n = 4) in three doses. Regarding safety, while mild to moderate adverse events were observed, no severe or serious adverse events occurred in all participants. For immunogenicity, the geometric mean fold rise (GMFR) in anti-IL-17A antibody was increased with peak at day 71 or 85 and continued until day 141. In ELISpot assay, the number of IL-4 and IFN-γ spots was increased in a dose dependent manner. Furthermore, circulating follicular helper T cells was significantly increased in the FPP003 high-dose group. The adjuvant-free FPP003 peptide vaccine could be well-tolerated and beneficial approach in human.