ADENOVIRUS-MEDIATED EXPRESSION OF THERAPEUTIC PLASMA-LEVELS OF HUMAN FACTOR-IX IN MICE

Gene therapy strategies designed to combat haemophilia B, caused by de fects in clotting factor IX, have so far concentrated on ex vivo appro aches. We have now evaluated adenoviral vector-mediated expression of human factor IX in vivo. Injection of the vector Av1H9B, which encodes human factor IX cDNA, into the tail veins of mice resulted in efficie nt liver transduction and plasma levels of human factor IX that would be therapeutic for haemophilia B patients. However, levels slowly decl ined to baseline by nine weeks and were not re-established by a second vector injection. These results address both the advantages and obsta cles to the use of adenoviral vectors for treatment of haemophilia B.