ATX-F8-117

ATX-F8-117 is a peptide-based antigen-specific immunotherapy composed of two optimized “apitopes” (P1 and P17) derived from immunodominant CD4 T‑cell epitopes of human coagulation factor VIII, designed to re‑establish immune tolerance to FVIII and thereby prevent or reduce the formation of neutralizing anti‑FVIII antibodies in hemophilia A patients receiving FVIII replacement therapy.[1][2] The peptides are engineered for solubility and direct binding to multiple HLA‑DRB1 alleles without prior antigen processing, promoting presentation by steady‑state dendritic cells and the induction or expansion of tolerogenic Tr1‑like regulatory T cells that suppress FVIII‑specific helper responses.[1][2] In HLA‑DR2 transgenic mouse models, subcutaneous administration of ATX‑F8‑117 using a dose‑escalation regimen markedly suppresses FVIII‑specific T‑cell proliferation, reduces inflammatory cytokine production, and significantly decreases both total anti‑FVIII IgG and inhibitor titers, supporting its development as a targeted tolerance‑inducing therapy for patients with or at risk of FVIII inhibitors in hemophilia A.[1][2][8][14]

Other names

FVIII apitope peptide cocktail P1 P17