title: Systemic delivery of an adenoviral vector encoding canine factor VIII results in short-term phenotypic correction, inhibitor development, and biphasic liver toxicity in hemophilia A dogs.
abstract: Canine hemophilia A closely mimics the human disease and has been used previously in the development of factor VIII (FVIII) protein replacement products. FVIII-deficient dogs were studied to evaluate an in vivo gene therapy approach using an E1/E2a/E3-deficient adenoviral vector encoding canine FVIII. Results demonstrated a high level of expression of the canine protein and complete phenotypic correction of the coagulation defect in all 4 treated animals. However, FVIII expression was short-term, lasting 5 to 10 days following vector infusion. All 4 dogs displayed a biphasic liver toxicity, a transient drop in platelets, and development of anticanine FVIII antibody. Canine FVIII inhibitor development was transient in 2 of the 4 treated animals. These data demonstrate that systemic delivery of attenuated adenoviral vectors resulted in liver toxicity and hematologic changes. Therefore, the development of further attenuated adenoviral vectors encoding canine FVIII will be required to improve vector safety and reduce the risk of immunologic sequelae, and may allow achievement of sustained phenotypic correction of canine hemophilia A.
authors.affiliation: Queen's University, Kingston, Ontario, Canada.
authors.forename: A M
authors.initials: AM
authors.lastname: Gallo-Penn
authors.forename: P S
authors.initials: PS
authors.lastname: Shirley
authors.forename: J L
authors.initials: JL
authors.lastname: Andrews
authors.forename: S
authors.initials: S
authors.lastname: Tinlin
authors.forename: S
authors.initials: S
authors.lastname: Webster
authors.forename: C
authors.initials: C
authors.lastname: Cameron
authors.forename: C
authors.initials: C
authors.lastname: Hough
authors.forename: C
authors.initials: C
authors.lastname: Notley
authors.forename: D
authors.initials: D
authors.lastname: Lillicrap
authors.forename: M
authors.initials: M
authors.lastname: Kaleko
authors.forename: S
authors.initials: S
authors.lastname: Connelly
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D001777:Blood Coagulation / Q000187:drug effects; D056486:Chemical and Drug Induced Liver Injury; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D005169:Factor VIII / Q000008:administration & dosage* / Q000235:genetics / Q000276:immunology*; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism; D005340:Fibrinogen / Q000378:metabolism; D015870:Gene Expression; D018014:Gene Transfer Techniques / Q000009:adverse effects / Q000592:standards*; D005822:Genetic Vectors / Q000008:administration & dosage / Q000592:standards / Q000633:toxicity; D006467:Hemophilia A / Q000150:complications / Q000188:drug therapy* / Q000276:immunology; D007518:Isoantibodies / Q000097:blood; D008107:Liver Diseases / Q000201:enzymology / Q000209:etiology; D008297:Male; D023421:Models, Animal; D010641:Phenotype; D010976:Platelet Count; D013997:Time Factors
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; D007518:Isoantibodies; D005169:Factor VIII; D005340:Fibrinogen