The present invention relates to a recombinant polypeptide comprising a truncated von Willebrand Factor (VWF) capable of binding to blood coagulation Factor VIII (FVIII) for use in reducing the immunogenicity of Factor VIII (FVIII) wherein said recombinant polypeptide and a blood coagulation Factor VIII (FVIII) protein are co-administered to a subject suffering from a 10 blood coagulation disorder. The invention further relates to pharmaceutical compositions and kits for said use.