The present invention provides peptides partly derivable from FVIII which are capable of binding to an MHC class II molecule without further antigen processing and being recognised by a factor VIII specific T cell. In particular, the present invention provides peptides comprising the sequence DNIMVTFRNQASRPY or PRCLTRYYSSFVNME with modifications at the N-and C-termini. The present invention also relates to the use of such a peptide for the prevention or suppression of inhibitor antibody formation in haemophilia A and/or acquired haemophilia.