{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,15]],"date-time":"2026-07-15T00:24:09Z","timestamp":1784075049966,"version":"3.55.0"},"reference-count":53,"publisher":"Wiley","issue":"9","license":[{"start":{"date-parts":[[2024,7,23]],"date-time":"2024-07-23T00:00:00Z","timestamp":1721692800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100019174","name":"Australian Companion Animal Health Foundation","doi-asserted-by":"publisher","award":["017\/2014"],"award-info":[{"award-number":["017\/2014"]}],"id":[{"id":"10.13039\/501100019174","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100019174","name":"Australian Companion Animal Health Foundation","doi-asserted-by":"publisher","award":["014\/2017"],"award-info":[{"award-number":["014\/2017"]}],"id":[{"id":"10.13039\/501100019174","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Aust Veterinary J"],"published-print":{"date-parts":[[2024,9]]},"abstract":"<jats:sec><jats:title>Background<\/jats:title><jats:p>It is doubtful that any of the treatments proposed for feline leukaemia virus (FeLV) infection are effective, despite the entity being described 60\u2009years ago.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Eighteen pet cats with progressive FeLV infections were recruited in Australia. One or more antiviral drugs were trialled in 16 cats, while two FeLV\u2010infected cats were not handleable and served as untreated controls. Six cats were administered RetroMAD1\u2122 only (0.5\u2009mg\/kg orally twice daily), a commercially available recombinant chimeric protein with proposed antiretroviral activity. Three cats were administered the integrase inhibitor raltegravir only (10\u201315\u2009mg\/kg orally twice daily), a drug used as a component of highly effective antiretroviral therapy for human immunodeficiency virus (HIV\u20101) infection. Three cats were administered RetroMAD1\u2122 and raltegravir concurrently, and four cats were administered raltegravir and the reverse transcriptase inhibitor zidovudine (AZT, 5\u2009mg\/kg orally twice daily) concurrently. FeLV RNA and p27 antigen loads were measured at two timepoints (T1\u20102\u2009months and T3\u20105\u2009months) during therapy and compared to baseline (pretreatment) levels, to assess the response to therapy using linear modelling. The median survival time (MST) of the cats from commencement of FeLV treatment to death was also determined and compared between treatments.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>The MST for the 16 FeLV\u2010positive cats which received antiviral therapy was 634\u2009days, while the MST from FeLV diagnosis to death for the two untreated control cats was 780\u2009days. In cats treated with RetroMAD1\u2122, FeLV viral load decreased from T0 to T1\u20102\u2009months (median viral load reduced from 1339 \u00d7\u200910<jats:sup>6<\/jats:sup> to 705 \u00d7\u200910<jats:sup>6<\/jats:sup> copies\/mL plasma; P\u2009=\u20090.012), but MST was reduced compared to cats not given RetroMAD1\u2122 (426\u2009days vs 1006\u2009days; P\u2009=\u20090.049). Cats treated with raltegravir and AZT had no significant changes in FeLV viral load over time, but p27 antigen load was decreased from T0 to T3\u20105\u2009months in cats treated with raltegravir (median p27 antigen level reduced from 50.2% to 42.7%; P\u2009=\u20090.005). All other results were not significantly affected by the treatment provided.<\/jats:p><jats:p>Importantly, statistically significant and substantial associations were found between age at FeLV diagnosis and survival time (P\u2009=\u20090.046, R<jats:sup>2<\/jats:sup>\u2009=\u200918.6) and between FeLV viral load at T0 and survival time (P\u2009=\u20090.004, R<jats:sup>2<\/jats:sup>\u2009=\u200944.4). Younger cats, and cats with higher levels of pretreatment FeLV RNA, had reduced survival times. Cats treated with RetroMAD1\u2122 were typically younger (median age 2.0 vs 8.0\u2009years), likely explaining the observed reduction in MST. A significant association was found between FeLV viral load and p27 antigen load at T0 (P\u2009=\u20090.015, R<jats:sup>2<\/jats:sup>\u2009=\u200932.9).<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>Results from this small case series do not provide convincing support for the use of RetroMAD1\u2122, raltegravir or AZT, alone or in combination, for the treatment of cats progressively infected with FeLV. The changes observed were biologically insignificant. Age and FeLV viral load at diagnosis are useful prognostic markers, and p27 antigen concentration can be used to predict viral load. Larger field trials should be performed examining antiretroviral therapy in FeLV\u2010positive cats with progressive infections, preferably using three or more drugs from at least two classes, as is standard with human antiretroviral therapy. Future studies would be easier in countries with a higher prevalence of FeLV infections than Australia.<\/jats:p><\/jats:sec>","DOI":"10.1111\/avj.13363","type":"journal-article","created":{"date-parts":[[2024,7,23]],"date-time":"2024-07-23T21:29:14Z","timestamp":1721770154000},"page":"453-465","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Antiviral therapy in cats progressively infected with feline leukaemia virus: lessons from a series of 18 consecutive cases from Australia"],"prefix":"10.1111","volume":"102","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7400-1960","authenticated-orcid":false,"given":"ME","family":"Westman","sequence":"first","affiliation":[{"name":"Sydney School of Veterinary Science The University of Sydney  Sydney New South Wales Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8999-9046","authenticated-orcid":false,"given":"E","family":"Hall","sequence":"additional","affiliation":[{"name":"Sydney School of Veterinary Science The University of Sydney  Sydney New South Wales Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0003-6930","authenticated-orcid":false,"given":"JM","family":"Norris","sequence":"additional","affiliation":[{"name":"Sydney School of Veterinary Science The University of Sydney  Sydney New South Wales Australia"},{"name":"Sydney Institute for Infectious Diseases The University of Sydney  Sydney New South Wales Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"T","family":"Meili","sequence":"additional","affiliation":[{"name":"Clinical Laboratory, Department of Clinical Diagnostics and Services, and Center for Clinical Studies, Vetsuisse Faculty The University of Zurich  Zurich Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9750-4296","authenticated-orcid":false,"given":"R","family":"Hofmann\u2010Lehmann","sequence":"additional","affiliation":[{"name":"Clinical Laboratory, Department of Clinical Diagnostics and Services, and Center for Clinical Studies, Vetsuisse Faculty The University of Zurich  Zurich Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6025-194X","authenticated-orcid":false,"given":"R","family":"Malik","sequence":"additional","affiliation":[{"name":"Centre for Veterinary Education The University of Sydney  Sydney New South Wales Australia"},{"name":"School of Veterinary and Animal Science Charles Sturt University  Wagga Wagga New South Wales Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2024,7,23]]},"reference":[{"key":"e_1_2_9_2_1","doi-asserted-by":"publisher","DOI":"10.3390\/v11110993"},{"key":"e_1_2_9_3_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.tvjl.2012.07.004"},{"key":"e_1_2_9_4_1","doi-asserted-by":"publisher","DOI":"10.3390\/v4020236"},{"key":"e_1_2_9_5_1","doi-asserted-by":"publisher","DOI":"10.1038\/202567a0"},{"key":"e_1_2_9_6_1","doi-asserted-by":"publisher","DOI":"10.2460\/javma.228.3.371"},{"issue":"2","key":"e_1_2_9_7_1","doi-asserted-by":"crossref","first-page":"187","DOI":"10.2460\/javma.251.2.187","article-title":"Seroprevalences of feline leukemia virus and feline immunodeficiency virus infection in cats in the United States and Canada and risk factors for seropositivity","volume":"251","author":"Burling AN","year":"2017","journal-title":"J Am Vet Med Assoc"},{"key":"e_1_2_9_8_1","doi-asserted-by":"publisher","DOI":"10.1177\/1098612X20941785"},{"key":"e_1_2_9_9_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.cvsm.2020.05.006"},{"key":"e_1_2_9_10_1","doi-asserted-by":"publisher","DOI":"10.1051\/vetres\/2009065"},{"issue":"8","key":"e_1_2_9_11_1","doi-asserted-by":"crossref","first-page":"1087","DOI":"10.1016\/j.vaccine.2005.09.010","article-title":"Reassessment of feline leukaemia virus (FeLV) vaccines with novel sensitive molecular assays","volume":"24","author":"Hofmann\u2010Lehmann R","year":"2006","journal-title":"Vaccine"},{"issue":"11","key":"e_1_2_9_12_1","first-page":"2054","article-title":"Course of feline leukemia virus infection and its detection by enzyme\u2010linked immunosorbent assay and monoclonal antibodies","volume":"44","author":"Lutz H","year":"1983","journal-title":"Am J Vet Res"},{"key":"e_1_2_9_13_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jfms.2009.05.005"},{"key":"e_1_2_9_14_1","doi-asserted-by":"publisher","DOI":"10.3390\/v4112684"},{"issue":"2","key":"e_1_2_9_15_1","first-page":"582","article-title":"Biology of feline leukemia virus in the natural environment","volume":"36","author":"Hardy WD","year":"1976","journal-title":"Cancer Res"},{"key":"e_1_2_9_16_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.virusres.2014.12.025"},{"issue":"6","key":"e_1_2_9_17_1","first-page":"623","article-title":"Feline immunodeficiency virus and feline leukemia virus infections and their relationships to lymphoid malignancies in cats: a retrospective study (1968\u20101988)","volume":"3","author":"Shelton GH","year":"1990","journal-title":"J Acquir Immune Defic Syndr"},{"key":"e_1_2_9_18_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1749-6632.1990.tb17846.x"},{"issue":"12","key":"e_1_2_9_19_1","doi-asserted-by":"crossref","first-page":"2715","DOI":"10.1128\/AAC.36.12.2715","article-title":"Pre\u2010and postexposure chemoprophylaxis: evidence that 3\u2032\u2010azido\u20103\u2032\u2010dideoxythymidine inhibits feline leukemia virus disease by a drug\u2010induced vaccine response","volume":"36","author":"Mathes L","year":"1992","journal-title":"Antimicrob Agents Chemother"},{"issue":"12","key":"e_1_2_9_20_1","first-page":"3190","article-title":"3\u2032\u2010Azido\u20103\u2032\u2010deoxythymidine in feline leukemia virus\u2010infected cats: a model for therapy and prophylaxis of AIDS","volume":"47","author":"Tavares L","year":"1987","journal-title":"Cancer Res"},{"issue":"1","key":"e_1_2_9_21_1","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1159\/000150121","article-title":"Testing of nucleoside analogues in cats infected with feline leukemia virus: a model","volume":"30","author":"Tavares L","year":"1989","journal-title":"Intervirology"},{"key":"e_1_2_9_22_1","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.38.7.1573"},{"issue":"8","key":"e_1_2_9_23_1","first-page":"787","article-title":"Zidovudine in combination with alpha interferon and interleukin\u20102 as prophylactic therapy for FeLV\u2010induced immunodeficiency syndrome (FeLV\u2010FAIDS)","volume":"3","author":"Zeidner NS","year":"1990","journal-title":"J Acquir Immune Defic Syndr"},{"key":"e_1_2_9_24_1","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.34.9.1749"},{"key":"e_1_2_9_25_1","doi-asserted-by":"publisher","DOI":"10.1177\/1098612X12473468"},{"key":"e_1_2_9_26_1","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1016\/B978-0-323-22652-3.00007-4","article-title":"Update on antiviral therapies","volume":"7","author":"Wilkes RP","year":"2016","journal-title":"August's Consultations Feline Internal Med"},{"key":"e_1_2_9_27_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1939-1676.2004.tb02570.x"},{"key":"e_1_2_9_28_1","doi-asserted-by":"publisher","DOI":"10.3390\/ani10091464"},{"issue":"3","key":"e_1_2_9_29_1","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1016\/j.vetimm.2011.06.008","article-title":"Use of recombinant interferon omega in feline retrovirosis: from theory to practice","volume":"143","author":"Dom\u00e9nech A","year":"2011","journal-title":"Vet Immunol Immunopathol"},{"key":"e_1_2_9_30_1","doi-asserted-by":"publisher","DOI":"10.3390\/v11090845"},{"key":"e_1_2_9_31_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.rvsc.2012.09.025"},{"key":"e_1_2_9_32_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.vetmic.2011.03.039"},{"issue":"2","key":"e_1_2_9_33_1","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1016\/j.vetmic.2014.10.031","article-title":"Evaluation of the effect of short\u2010term treatment with the integrase inhibitor raltegravir (Isentress) on the course of progressive feline leukemia virus infection","volume":"175","author":"Boesch A","year":"2015","journal-title":"Vet Microbiol"},{"key":"e_1_2_9_34_1","doi-asserted-by":"crossref","DOI":"10.29374\/2527-2179.bjvm003522","article-title":"Undetectable proviral DNA and viral RNA levels after raltegravir administration in two cats with natural feline leukemia virus infection","volume":"44","author":"Santos C","year":"2022","journal-title":"Braz J Vet Med"},{"key":"e_1_2_9_35_1","doi-asserted-by":"publisher","DOI":"10.22363\/2312-797X-2023-18-3-411-417"},{"issue":"4","key":"e_1_2_9_36_1","first-page":"41","article-title":"Case studies on RetroMAD1\u2122, an orally administered recombinant chimeric protein to treat naturally infected feline leukemia virus (FeLV) cats","volume":"2","author":"Huan UE","year":"2019","journal-title":"Arch Vet Sci Med"},{"key":"e_1_2_9_37_1","unstructured":"https:\/\/www.abcdcatsvets.org\/guideline-for-feline-leukaemia-virus-infection\/."},{"key":"e_1_2_9_38_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jviromet.2005.06.017"},{"key":"e_1_2_9_39_1","doi-asserted-by":"publisher","DOI":"10.3390\/v11060503"},{"issue":"2","key":"e_1_2_9_40_1","doi-asserted-by":"crossref","first-page":"209","DOI":"10.1016\/0022-1759(83)90413-1","article-title":"Monoclonal antibodies to three epitopic regions of feline leukemia virus p27 and their use in enzyme\u2010linked immunosorbent assay of p27","volume":"56","author":"Lutz H","year":"1983","journal-title":"J Immunol Methods"},{"key":"e_1_2_9_41_1","doi-asserted-by":"publisher","DOI":"10.1099\/0022-1317-82-7-1589"},{"key":"e_1_2_9_42_1","doi-asserted-by":"publisher","DOI":"10.1177\/1098612X20941784"},{"key":"e_1_2_9_43_1","doi-asserted-by":"publisher","DOI":"10.1111\/jsap.13718"},{"key":"e_1_2_9_44_1","doi-asserted-by":"publisher","DOI":"10.3390\/v13020302"},{"issue":"1","key":"e_1_2_9_45_1","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1016\/j.vetmic.2005.10.027","article-title":"Shedding of feline leukemia virus RNA in saliva is a consistent feature in viremic cats","volume":"112","author":"Gomes\u2010Keller MA","year":"2006","journal-title":"Vet Microbiol"},{"key":"e_1_2_9_46_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.cimid.2019.101348"},{"key":"e_1_2_9_47_1","doi-asserted-by":"publisher","DOI":"10.1038\/nm0696-625"},{"key":"e_1_2_9_48_1","unstructured":"World Health Organization.Consolidated guidelines on HIV prevention testing treatment service delivery and monitoring: recommendations for a public health approach.2021."},{"key":"e_1_2_9_49_1","doi-asserted-by":"publisher","DOI":"10.1046\/j.1529-8019.2000.00032.x"},{"key":"e_1_2_9_50_1","doi-asserted-by":"publisher","DOI":"10.1177\/1098612X19895940"},{"key":"e_1_2_9_51_1","doi-asserted-by":"publisher","DOI":"10.1080\/17425247.2022.2121817"},{"key":"e_1_2_9_52_1","unstructured":"Centre for Health Protection.Recommended principles of antiretroviral therapy in HIV disease.2011."},{"key":"e_1_2_9_53_1","doi-asserted-by":"publisher","DOI":"10.3390\/v13081636"},{"key":"e_1_2_9_54_1","first-page":"1","article-title":"A retrospective examination of feline leukemia subgroup characterization: viral interference assays to deep sequencing","volume":"10","author":"Chiu ES","year":"2018","journal-title":"Viruses"}],"container-title":["Australian Veterinary Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/avj.13363","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,9,2]],"date-time":"2024-09-02T05:37:21Z","timestamp":1725255441000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/avj.13363"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,7,23]]},"references-count":53,"journal-issue":{"issue":"9","published-print":{"date-parts":[[2024,9]]}},"alternative-id":["10.1111\/avj.13363"],"URL":"https:\/\/doi.org\/10.1111\/avj.13363","archive":["Portico"],"relation":{},"ISSN":["0005-0423","1751-0813"],"issn-type":[{"value":"0005-0423","type":"print"},{"value":"1751-0813","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,7,23]]},"assertion":[{"value":"2023-12-15","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-07-03","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-07-23","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}