{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,7]],"date-time":"2026-11-07T17:36:07Z","timestamp":1794072967473,"version":"4.8.0"},"reference-count":36,"publisher":"American Society of Hematology","issue":"25","content-domain":{"domain":["ashpublications.org"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2022,12,22]]},"abstract":"<jats:title>Abstract<\/jats:title>\n               <jats:p>Questions remain concerning the long-term efficacy, safety, and site(s) of transgene expression following adeno-associated vector (AAV) therapy. We report a long-term follow-up of 8 (male = 4, hemizygous, and female = 4, homozygous) dogs with severe hemophilia A treated with a single portal vein infusion of a B-domain\u2013deleted (BDD)-canine FVIII (cFVIII) AAV vector (median dose = 1.25 \u00d7 1013 vg\/kg, AAV2 = 4, AAV6 = 3, and AAV8 = 1). After a median follow-up of 10.8 years (8.2-12.0 years), persistent FVIII:C (median one-stage = 12.7%, chromogenic = 7.2%) was seen in all responding dogs (n = 6), with improvement in annualized bleed rates (pre = 3.9 vs post = 0.3 event per year; P\u00a0=\u00a0.003). Anti-AAV capsid neutralizing antibodies (nAbs) toward the dosed capsid were detected throughout the study, with limited cross-reactivity to other capsids. nAb titers for all capsid serotypes declined with time, although they remained at levels precluding redosing with the same capsid. AAV-BDD-cFVIII DNA was detected in the liver of all dogs (median = 0.15 vg per diploid genome), with lower levels in the spleen in 4 dogs (median = 0.005 vg per diploid genome). Consistent with the liver-specific promoter, BDD-cFVIII mRNA was only detected in the liver. Postmortem examination demonstrated no evidence of chronic liver disease or liver malignancy. Persistent FVIII expression and an improved bleeding phenotype was seen for more than a decade after vector delivery. This is the longest follow-up reported in a preclinical model supporting long-term efficacy and safety of AAV-mediated gene therapy.<\/jats:p>","DOI":"10.1182\/blood.2021014735","type":"journal-article","created":{"date-parts":[[2022,4,11]],"date-time":"2022-04-11T19:06:38Z","timestamp":1649703998000},"page":"2672-2683","update-policy":"https:\/\/doi.org\/10.1182\/blood.2019cm0000","source":"Crossref","is-referenced-by-count":39,"title":["Long-term follow-up of liver-directed, adeno-associated vector-mediated gene therapy in the canine model of hemophilia A"],"prefix":"10.1182","volume":"140","author":[{"given":"P.","family":"Batty","sequence":"first","affiliation":[{"name":"1Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A. M.","family":"Mo","sequence":"additional","affiliation":[{"name":"1Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"D.","family":"Hurlbut","sequence":"additional","affiliation":[{"name":"1Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J.","family":"Ishida","sequence":"additional","affiliation":[{"name":"2Vector Biology, BioMarin Pharmaceutical Inc, Novato, CA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"B.","family":"Yates","sequence":"additional","affiliation":[{"name":"3Biology Research, BioMarin Pharmaceutical Inc, Novato, CA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"C.","family":"Brown","sequence":"additional","affiliation":[{"name":"1Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"L.","family":"Harpell","sequence":"additional","affiliation":[{"name":"1Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"C.","family":"Hough","sequence":"additional","affiliation":[{"name":"1Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A.","family":"Pender","sequence":"additional","affiliation":[{"name":"1Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"E. K.","family":"Rimmer","sequence":"additional","affiliation":[{"name":"1Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S.","family":"Sardo Infirri","sequence":"additional","affiliation":[{"name":"1Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A.","family":"Winterborn","sequence":"additional","affiliation":[{"name":"1Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S.","family":"Fong","sequence":"additional","affiliation":[{"name":"3Biology Research, BioMarin Pharmaceutical Inc, Novato, CA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"D.","family":"Lillicrap","sequence":"additional","affiliation":[{"name":"1Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"234","reference":[{"issue":"5992","key":"2022122216260698700_bib1","doi-asserted-by":"crossref","first-page":"326","DOI":"10.1038\/312326a0","article-title":"Characterization of the human factor\u00a0VIII\u00a0gene","volume":"312","author":"Gitschier","year":"1984","journal-title":"Nature"},{"issue":"21","key":"2022122216260698700_bib2","doi-asserted-by":"crossref","first-page":"6461","DOI":"10.1073\/pnas.79.21.6461","article-title":"Isolation and characterization of a cDNA coding for human factor IX","volume":"79","author":"Kurachi","year":"1982","journal-title":"Proc Natl Acad Sci USA"},{"issue":"3","key":"2022122216260698700_bib3","doi-asserted-by":"crossref","first-page":"e540","DOI":"10.1097\/HS9.0000000000000540","article-title":"Hemophilia gene therapy: approaching the first licensed product","volume":"5","author":"Batty","year":"2021","journal-title":"HemaSphere"},{"issue":"4","key":"2022122216260698700_bib4","doi-asserted-by":"crossref","first-page":"659","DOI":"10.1055\/s-0037-1613063","article-title":"Aberrant splicing and premature termination of transcription of the FVIII gene as a cause of severe canine hemophilia A: similarities with the intron 22 inversion mutation in human hemophilia","volume":"87","author":"Hough","year":"2002","journal-title":"Thromb Haemost"},{"issue":"3","key":"2022122216260698700_bib5","doi-asserted-by":"crossref","first-page":"727","DOI":"10.1182\/blood.V60.3.727.727","article-title":"A\u00a0canine model of hemophilic (factor VIII:C deficiency) bleeding","volume":"60","author":"Giles","year":"1982","journal-title":"Blood"},{"issue":"1","key":"2022122216260698700_bib6","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1055\/s-0038-1651541","article-title":"The development of homologous (canine\/anti-canine) antibodies in dogs with haemophilia A (factor VIII deficiency): a ten-year longitudinal study","volume":"69","author":"Tinlin","year":"1993","journal-title":"Thromb Haemost"},{"issue":"11","key":"2022122216260698700_bib7","doi-asserted-by":"crossref","first-page":"2469","DOI":"10.1111\/j.1538-7836.2010.04053.x","article-title":"The expanding menagerie: animal models of hemophilia A","volume":"8","author":"Monahan","year":"2010","journal-title":"J\u00a0Thromb Haemost"},{"issue":"1","key":"2022122216260698700_bib8","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1182\/blood-2005-12-5115","article-title":"Multiyear therapeutic benefit of AAV serotypes 2, 6, and 8 delivering factor VIII to hemophilia A mice and dogs","volume":"108","author":"Jiang","year":"2006","journal-title":"Blood"},{"issue":"6","key":"2022122216260698700_bib9","doi-asserted-by":"crossref","first-page":"2031","DOI":"10.1182\/blood-2003-01-0292","article-title":"Sustained phenotypic correction of canine hemophilia A using an adeno-associated viral vector","volume":"102","author":"Scallan","year":"2003","journal-title":"Blood"},{"issue":"20","key":"2022122216260698700_bib10","doi-asserted-by":"crossref","first-page":"4562","DOI":"10.1182\/blood-2009-05-220327","article-title":"Recombinant canine B-domain-deleted FVIII exhibits high specific activity and is safe in the canine hemophilia A model","volume":"114","author":"Sabatino","year":"2009","journal-title":"Blood"},{"issue":"11","key":"2022122216260698700_bib11","doi-asserted-by":"crossref","first-page":"1935","DOI":"10.1111\/jth.12672","article-title":"Subcommittee on Factor VIII, Factor IX and Rare Coagulation Disorders of the Scientific and Standardization Committee of the International Society on Thrombosis and Hemostasis. Definitions in hemophilia: communication from the SSC of the ISTH","volume":"12","author":"Blanchette","year":"2014","journal-title":"J\u00a0Thromb Haemost"},{"issue":"2","key":"2022122216260698700_bib12","first-page":"612","article-title":"Proceedings: a more uniform measurement of factor VIII inhibitors","volume":"34","author":"Kasper","year":"1975","journal-title":"Thromb Diath Haemorrh"},{"issue":"22","key":"2022122216260698700_bib13","doi-asserted-by":"crossref","first-page":"2524","DOI":"10.1182\/blood.2020005683","article-title":"Activity of transgene-produced B-domain-deleted factor VIII in human plasma following AAV5 gene therapy","volume":"136","author":"Rosen","year":"2020","journal-title":"Blood"},{"issue":"1","key":"2022122216260698700_bib14","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1038\/s41587-020-0741-7","article-title":"A\u00a0long-term study of AAV gene therapy in dogs with hemophilia A identifies clonal expansions of transduced liver cells","volume":"39","author":"Nguyen","year":"2021","journal-title":"Nat Biotechnol"},{"key":"2022122216260698700_bib15","first-page":"ABS021","article-title":"Characterisation of adeno-associated virus vector persistence after long-term follow up in the haemophilia a dog model","volume":"27","author":"Batty","year":"2021","journal-title":"Haemophilia"},{"issue":"6","key":"2022122216260698700_bib16","doi-asserted-by":"crossref","first-page":"947","DOI":"10.1111\/hae.14391","article-title":"Persistence of haemostatic response following gene therapy with valoctocogene roxaparvovec in severe haemophilia A","volume":"27","author":"Pasi","year":"2021","journal-title":"Haemophilia"},{"issue":"11","key":"2022122216260698700_bib17","doi-asserted-by":"crossref","first-page":"1013","DOI":"10.1056\/NEJMoa2113708","article-title":"Valoctocogene Roxaparvovec Gene Therapy for Hemophilia A","volume":"386","author":"Ozelo","year":"2022","journal-title":"N Engl J Med"},{"issue":"2","key":"2022122216260698700_bib18","first-page":"127","article-title":"An anatomical study of senescence in dogs, with especial reference to the relation of cellular changes of age to tumors","volume":"38","author":"Goodpasture","year":"1918","journal-title":"J\u00a0Med Res"},{"issue":"2","key":"2022122216260698700_bib19","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1177\/030098588201900202","article-title":"Nodular hyperplasia of the liver in the beagle dog","volume":"19","author":"Fabry","year":"1982","journal-title":"Vet Pathol"},{"issue":"5","key":"2022122216260698700_bib20","doi-asserted-by":"crossref","first-page":"427","DOI":"10.1177\/030098588502200501","article-title":"Nodular hyperplasia in the liver of the dog: an association with changes in the Ito cell population","volume":"22","author":"Bergman","year":"1985","journal-title":"Vet Pathol"},{"key":"2022122216260698700_bib21","volume-title":"Tumors in domestic animals","author":"Cullen","year":"2017","edition":"5th ed."},{"issue":"4","key":"2022122216260698700_bib22","doi-asserted-by":"crossref","first-page":"797","DOI":"10.1182\/blood-2008-10-181479","article-title":"Long-term correction of inhibitor-prone hemophilia B dogs treated with liver-directed AAV2-mediated factor IX gene therapy","volume":"113","author":"Niemeyer","year":"2009","journal-title":"Blood"},{"issue":"S1","key":"2022122216260698700_bib23","article-title":"Adeno-associated mediated gene transfer for hemophilia B: 8 year follow up and impact of removing \u201cempty viral particles\u201d on safety and efficacy of gene transfer [abstract]","volume":"132","author":"Nathwani","year":"2018","journal-title":"Blood"},{"issue":"9","key":"2022122216260698700_bib24","doi-asserted-by":"crossref","first-page":"2073","DOI":"10.1016\/j.ymthe.2020.06.001","article-title":"Long-term follow-up of the first in human intravascular delivery of AAV for gene transfer: AAV2-hFIX16 for severe hemophilia B","volume":"28","author":"George","year":"2020","journal-title":"Mol Ther"},{"issue":"S1","key":"2022122216260698700_bib25","first-page":"OC 03.4","article-title":"First in human liver biopsy study following gene therapy for hemophilia A","volume":"4","author":"Fong","year":"2020","journal-title":"Res Pract Thromb Haemost"},{"issue":"3","key":"2022122216260698700_bib26","doi-asserted-by":"crossref","first-page":"381","DOI":"10.1086\/595830","article-title":"Worldwide epidemiology of neutralizing antibodies to adeno-associated viruses","volume":"199","author":"Calcedo","year":"2009","journal-title":"J\u00a0Infect Dis"},{"issue":"6","key":"2022122216260698700_bib27","doi-asserted-by":"crossref","first-page":"704","DOI":"10.1089\/hum.2009.182","article-title":"Prevalence of serum IgG and neutralizing factors against adeno-associated virus (AAV) types 1, 2, 5, 6, 8, and 9 in the healthy population: implications for gene therapy using AAV vectors","volume":"21","author":"Boutin","year":"2010","journal-title":"Hum Gene Ther"},{"issue":"12","key":"2022122216260698700_bib28","doi-asserted-by":"crossref","first-page":"768","DOI":"10.1038\/gt.2017.95","article-title":"Strategy to detect pre-existing immunity to AAV gene therapy","volume":"24","author":"Falese","year":"2017","journal-title":"Gene Ther"},{"issue":"2","key":"2022122216260698700_bib29","doi-asserted-by":"crossref","first-page":"261","DOI":"10.1002\/rth2.12177","article-title":"Adenovirus-associated antibodies in UK cohort of hemophilia patients: A seroprevalence study of the presence of adenovirus-associated virus vector-serotypes AAV5 and AAV8 neutralizing activity and\u00a0antibodies in patients with hemophilia A","volume":"3","author":"Stanford","year":"2019","journal-title":"Res Pract Thromb Haemost"},{"issue":"1","key":"2022122216260698700_bib30","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1038\/mt.2011.177","article-title":"Neutralizing antibodies against AAV serotypes 1, 2, 6, and 9 in sera of commonly used animal models","volume":"20","author":"Rapti","year":"2012","journal-title":"Mol Ther"},{"issue":"3","key":"2022122216260698700_bib31","doi-asserted-by":"crossref","first-page":"287","DOI":"10.1089\/hum.2011.125","article-title":"Humoral immunity to AAV-6, 8, and 9 in normal and dystrophic dogs","volume":"23","author":"Shin","year":"2012","journal-title":"Hum Gene Ther"},{"key":"2022122216260698700_bib32","doi-asserted-by":"crossref","first-page":"14002","DOI":"10.1038\/mtm.2014.2","article-title":"Systemic gene transfer reveals distinctive muscle transduction profile of tyrosine mutant AAV-1, -6, and -9 in neonatal dogs","volume":"1","author":"Hakim","year":"2014","journal-title":"Mol Ther Methods Clin Dev"},{"issue":"3","key":"2022122216260698700_bib33","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1089\/hgtb.2015.082","article-title":"Preexisting neutralizing antibodies to adeno-associated virus capsids in large animals other than monkeys may confound in\u00a0vivo gene therapy studies","volume":"26","author":"Calcedo","year":"2015","journal-title":"Hum Gene Ther Methods"},{"issue":"11","key":"2022122216260698700_bib34","doi-asserted-by":"crossref","first-page":"2084","DOI":"10.1038\/mt.2011.108","article-title":"A\u00a010 patient case report on the impact of plasmapheresis upon neutralizing factors against adeno-associated virus (AAV) types 1, 2, 6, and 8","volume":"19","author":"Monteilhet","year":"2011","journal-title":"Mol Ther"},{"issue":"17","key":"2022122216260698700_bib35","doi-asserted-by":"crossref","first-page":"2632","DOI":"10.1182\/bloodadvances.2019000380","article-title":"Immunoadsorption enables successful rAAV5-mediated repeated hepatic gene delivery in nonhuman primates","volume":"3","author":"Salas","year":"2019","journal-title":"Blood Adv"},{"issue":"7","key":"2022122216260698700_bib36","doi-asserted-by":"crossref","first-page":"1096","DOI":"10.1038\/s41591-020-0911-7","article-title":"IgG-cleaving endopeptidase enables in\u00a0vivo gene therapy in the presence of anti-AAV neutralizing antibodies","volume":"26","author":"Leborgne","year":"2020","journal-title":"Nat Med"}],"container-title":["Blood"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/ashpublications.org\/blood\/article-pdf\/140\/25\/2672\/2025503\/blood_bld-2021-014735-main.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/ashpublications.org\/blood\/article-pdf\/140\/25\/2672\/2025503\/blood_bld-2021-014735-main.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,12,22]],"date-time":"2022-12-22T16:27:07Z","timestamp":1671726427000},"score":1,"resource":{"primary":{"URL":"https:\/\/ashpublications.org\/blood\/article\/140\/25\/2672\/484676\/Long-term-follow-up-of-liver-directed-adeno"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,12,22]]},"references-count":36,"journal-issue":{"issue":"25","published-print":{"date-parts":[[2022,12,22]]}},"URL":"https:\/\/doi.org\/10.1182\/blood.2021014735","relation":{},"ISSN":["0006-4971","1528-0020"],"issn-type":[{"value":"0006-4971","type":"print"},{"value":"1528-0020","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,12,22]]}}}