Transfer of the feline erythropoietin gene to cats using a recombinant adeno-associated virus vector

Chronic renal failure and the associated erythropoietin-responsive anemia a fflicts over 2 million domestic cats in the United States, resulting in mor bidity that can affect the owner-pet relationship. Although treatment of ca ts with recombinant human erythropoietin (Epo) protein can be effective, re sponse to the drug often dissipates over time, probably due to the developm ent of antibodies reactive with the human protein. As an alternate approach to the treatment of this disease, we have developed a recombinant adeno-as sociated virus vector containing the feline erythropoietin gene (rAAV/feEpo ). This vector, when administered intramuscularly to normal healthy cats, c aused a dose-related increase in hematocrit over a 7-week period after inje ction. Thus, the rAAV/feEpo vector holds promise as a simple, safe and effe ctive therapy for the anemia of chronic renal failure in domestic cats.