The present invention relates to modified nucleic acid sequences coding for coagulationfactors preferably coagulation factor VIII and their derivatives, recombinantexpression vectors containing such nucleic acid sequences, host cells transformedwith such recombinant expression vectors, recombinant polypeptides and derivativescoded for by said nucleic acid sequences which recombinant polypeptides andderivatives do have biological activities and prolonged in vivo half-life comparedto the unmodified wild-type protein. The invention also relates to correspondingsequences that result in improved in vitro stability. The present inventionfurther relates to processes for the manufacture of such recombinant proteinsand their derivatives are covered. The invention also relates to a transfer vectorfor use in human gene therapy, which comprises such modified nucleic acid sequences.
