{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,2]],"date-time":"2026-10-02T21:01:02Z","timestamp":1790974862963,"version":"4.1.0"},"reference-count":36,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2025,7,19]],"date-time":"2025-07-19T00:00:00Z","timestamp":1752883200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pathogens"],"abstract":"<jats:p>Feline infectious peritonitis (FIP) is a severe viral disease with a very high fatality rate. GS-441524 is an adenosine analogue that acts as an antiviral and has shown promise in FIP treatment. However, its commercialization in some regions is not yet authorized. To evaluate the efficacy of GS-441524 based on the published literature, a systematic review was conducted. This systematic review was conducted using PubMed, ScienceDirect, and Google Scholar for studies published from 2018 onwards. Following PRISMA guidelines, 11 studies (totaling 650 FIP cases treated with GS-441524 alone or in combination) were included. Therapeutic efficacy was assessed by FIP form, clinical signs, and dosage. The overall treatment success rate was 84.6%. This rate was higher when GS-441524 was combined with other antivirals and lower in cases of wet FIP or those with neurological complications. Combination therapy with other antivirals may improve outcomes in complicated FIP cases, although further studies are needed. The GS-441524 dosages associated with the best outcomes were 5\u201310 mg\/kg once daily (or equivalent subcutaneous dose), adjusted for FIP type, severity, and presence of neurological\/ocular signs. Higher dosages can be used for severe cases or to prevent relapse, but splitting into twice-daily dosing may be necessary to avoid absorption issues. In summary, this synthesis indicates that GS-441524 is a highly promising treatment for FIP, with a high success rate among treated cases. Nevertheless, randomized controlled trials are needed to establish evidence-based therapeutic protocols tailored to different FIP presentations.<\/jats:p>","DOI":"10.3390\/pathogens14070717","type":"journal-article","created":{"date-parts":[[2025,7,21]],"date-time":"2025-07-21T09:33:53Z","timestamp":1753090433000},"page":"717","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Efficacy of GS-441524 for Feline Infectious Peritonitis: A Systematic Review (2018\u20132024)"],"prefix":"10.3390","volume":"14","author":[{"given":"Emma","family":"Gokalsing","sequence":"first","affiliation":[{"name":"Vasco da Gama Research Centre (CIVG), Department of Veterinary Sciences, Vasco da Gama University School, Avenida Jos\u00e9 R. Sousa Fernandes 197 Lordem\u00e3o, 3020-210 Coimbra, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1300-4487","authenticated-orcid":false,"given":"Joana","family":"Ferrolho","sequence":"additional","affiliation":[{"name":"Vasco da Gama Research Centre (CIVG), Department of Veterinary Sciences, Vasco da Gama University School, Avenida Jos\u00e9 R. Sousa Fernandes 197 Lordem\u00e3o, 3020-210 Coimbra, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9732-8915","authenticated-orcid":false,"given":"Mark S.","family":"Gibson","sequence":"additional","affiliation":[{"name":"Vasco da Gama Research Centre (CIVG), Department of Veterinary Sciences, Vasco da Gama University School, Avenida Jos\u00e9 R. Sousa Fernandes 197 Lordem\u00e3o, 3020-210 Coimbra, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3976-1619","authenticated-orcid":false,"given":"Hugo","family":"Vilhena","sequence":"additional","affiliation":[{"name":"Vasco da Gama Research Centre (CIVG), Department of Veterinary Sciences, Vasco da Gama University School, Avenida Jos\u00e9 R. Sousa Fernandes 197 Lordem\u00e3o, 3020-210 Coimbra, Portugal"},{"name":"Department of Veterinary Clinics, School of Medicine and Biomedical Sciences, ICBAS-UP, University of Porto, 4050-313 Porto, Portugal"},{"name":"Animal and Veterinary Research Centre (CECAV), University of Tr\u00e1s-os-Montes and Alto Douro (UTAD), Quinta de Prados, 5000-801 Vila Real, Portugal"},{"name":"Associate Laboratory for Animal and Veterinary Science\u2014AL4AnimalS, 1300-477 Lisboa, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0916-2044","authenticated-orcid":false,"given":"Sofia","family":"Anast\u00e1cio","sequence":"additional","affiliation":[{"name":"Vasco da Gama Research Centre (CIVG), Department of Veterinary Sciences, Vasco da Gama University School, Avenida Jos\u00e9 R. Sousa Fernandes 197 Lordem\u00e3o, 3020-210 Coimbra, Portugal"},{"name":"Center of Neurosciences and Cell Biology, Health Science Campus, 3000-548 Coimbra, Portugal"},{"name":"University Institute of Health Sciences\u2013CESPU (IUCS-CESPU), 4585-116 Gandra, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,7,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Delaplace, M., Huet, H., Gambino, A., and Le Poder, S. (2021). Feline Coronavirus Antivirals: A Review. Pathogens, 10.","DOI":"10.3390\/pathogens10091150"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1016\/j.tvjl.2014.04.016","article-title":"An update on feline infectious peritonitis: Diagnostics and therapeutics","volume":"201","author":"Pedersen","year":"2014","journal-title":"Vet. J."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"199059","DOI":"10.1016\/j.virusres.2023.199059","article-title":"An updated review of feline coronavirus: Mind the two biotypes","volume":"326","author":"Gao","year":"2023","journal-title":"Virus Res."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"594","DOI":"10.1016\/j.jfms.2009.05.008","article-title":"Feline infectious peritonitis. ABCD guidelines on prevention and management","volume":"11","author":"Addie","year":"2009","journal-title":"J. Feline Med. Surg."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"905","DOI":"10.1177\/1098612X221118761","article-title":"2022 AAFP\/EveryCat Feline Infectious Peritonitis Diagnosis Guidelines","volume":"24","author":"Thayer","year":"2022","journal-title":"J. Feline Med. Surg."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Tasker, S., Addie, D.D., Egberink, H., Hofmann-Lehmann, R., Hosie, M.J., Truyen, U., Belak, S., Boucraut-Baralon, C., Frymus, T., and Lloret, A. (2023). Feline Infectious Peritonitis: European Advisory Board on Cat Diseases Guidelines. Viruses, 15.","DOI":"10.3390\/v15091847"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"322","DOI":"10.1080\/01652176.2020.1845917","article-title":"Current status on treatment options for feline infectious peritonitis and SARS-CoV-2 positive cats","volume":"40","author":"Izes","year":"2020","journal-title":"Vet. Q."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1772","DOI":"10.1111\/jvim.16803","article-title":"Outcomes of treatment of cats with feline infectious peritonitis using parenterally administered remdesivir, with or without transition to orally administered GS-441524","volume":"37","author":"Coggins","year":"2023","journal-title":"J. Vet. Intern. Med."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Roy, M., Jacque, N., Novicoff, W., Li, E., Negash, R., and Evans, S.J.M. (2022). Unlicensed Molnupiravir is an Effective Rescue Treatment Following Failure of Unlicensed GS-441524-like Therapy for Cats with Suspected Feline Infectious Peritonitis. Pathogens, 11.","DOI":"10.3390\/pathogens11101209"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1098612x231194460","DOI":"10.1177\/1098612X231194460","article-title":"Retrospective study and outcome of 307 cats with feline infectious peritonitis treated with legally sourced veterinary compounded preparations of remdesivir and GS-441524 (2020\u20132022)","volume":"25","author":"Taylor","year":"2023","journal-title":"J. Feline Med. Surg."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1177\/1098612X19825701","article-title":"Efficacy and safety of the nucleoside analog GS-441524 for treatment of cats with naturally occurring feline infectious peritonitis","volume":"21","author":"Pedersen","year":"2019","journal-title":"J. Feline Med. Surg."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"227","DOI":"10.20344\/amp.11923","article-title":"Stages for Undertaking a Systematic Review","volume":"32","author":"Donato","year":"2019","journal-title":"Acta. Med. Port."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1186\/s13643-021-01626-4","article-title":"The PRISMA 2020 statement: An updated guideline for reporting systematic reviews","volume":"10","author":"Page","year":"2021","journal-title":"Syst. Rev."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Katayama, M., and Uemura, Y. (2021). Therapeutic Effects of Mutian((R)) Xraphconn on 141 Client-Owned Cats with Feline Infectious Peritonitis Predicted by Total Bilirubin Levels. Vet. Sci., 8.","DOI":"10.3390\/vetsci8120328"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Katayama, M., and Uemura, Y. (2023). Prognostic Prediction for Therapeutic Effects of Mutian on 324 Client-Owned Cats with Feline Infectious Peritonitis Based on Clinical Laboratory Indicators and Physical Signs. Vet. Sci., 10.","DOI":"10.3390\/vetsci10020136"},{"key":"ref_16","unstructured":"Pedersen, N.C. (2025, May 19). Neurological and Ocular FIP. Available online: https:\/\/www.sockfip.org\/2021-dr-pedersen-new-years-update-neurological-ocular-fip\/."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1587","DOI":"10.1111\/jvim.15780","article-title":"Antiviral treatment using the adenosine nucleoside analogue GS-441524 in cats with clinically diagnosed neurological feline infectious peritonitis","volume":"34","author":"Dickinson","year":"2020","journal-title":"J. Vet. Intern. Med."},{"key":"ref_18","first-page":"163","article-title":"Conducting systematic reviews of association (etiology): The Joanna Briggs Institute\u2019s approach","volume":"13","author":"Moola","year":"2015","journal-title":"JBI Evid. Implement."},{"key":"ref_19","first-page":"2127","article-title":"Methodological quality of case series studies: An introduction to the JBI critical appraisal tool","volume":"18","author":"Munn","year":"2020","journal-title":"JBI Evid. Synth."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"383","DOI":"10.1016\/j.jclinepi.2010.04.026","article-title":"GRADE guidelines: 1. Introduction-GRADE evidence profiles and summary of findings tables","volume":"64","author":"Guyatt","year":"2011","journal-title":"J. Clin. Epidemiol."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Addie, D.D., Silveira, C., Aston, C., Brauckmann, P., Covell-Ritchie, J., Felstead, C., Fosbery, M., Gibbins, C., Macaulay, K., and McMurrough, J. (2022). Alpha-1 Acid Glycoprotein Reduction Differentiated Recovery from Remission in a Small Cohort of Cats Treated for Feline Infectious Peritonitis. Viruses, 14.","DOI":"10.21203\/rs.3.rs-1145695\/v1"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1784","DOI":"10.1111\/jvim.16804","article-title":"Thirty-two cats with effusive or non-effusive feline infectious peritonitis treated with a combination of remdesivir and GS-441524","volume":"37","author":"Green","year":"2023","journal-title":"J. Vet. Intern. Med."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Lv, J., Bai, Y., Wang, Y., Yang, L., Jin, Y., and Dong, J. (2022). Effect of GS-441524 in combination with the 3C-like protease inhibitor GC376 on the treatment of naturally transmitted feline infectious peritonitis. Front. Vet. Sci., 9.","DOI":"10.3389\/fvets.2022.1002488"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"226","DOI":"10.1016\/j.vetmic.2018.04.026","article-title":"The nucleoside analog GS-441524 strongly inhibits feline infectious peritonitis (FIP) virus in tissue culture and experimental cat infection studies","volume":"219","author":"Murphy","year":"2018","journal-title":"Vet. Microbiol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"378","DOI":"10.1177\/1098612X17729626","article-title":"Efficacy of a 3C-like protease inhibitor in treating various forms of acquired feline infectious peritonitis","volume":"20","author":"Pedersen","year":"2018","journal-title":"J. Feline Med. Surg."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Krentz, D., Zenger, K., Alberer, M., Felten, S., Bergmann, M., Dorsch, R., Matiasek, K., Kolberg, L., Hofmann-Lehmann, R., and Meli, M.L. (2021). Curing Cats with Feline Infectious Peritonitis with an Oral Multi-Component Drug Containing GS-441524. Viruses, 13.","DOI":"10.3390\/v13112228"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"370","DOI":"10.1111\/jvim.16954","article-title":"Uroliths composed of antiviral compound GS-441524 in 2 cats undergoing treatment for feline infectious peritonitis","volume":"38","author":"Allinder","year":"2024","journal-title":"J. Vet. Intern. Med."},{"key":"ref_28","unstructured":"Pedersen, N.C. (2025, May 19). Summary of GS-441524 Treatment for FIP. Sock It to FIP. Available online: https:\/\/www.sockfip.org\/2020-dr-pedersen-gs-441524-update\/."},{"key":"ref_29","first-page":"1193","article-title":"Effect of feline interferon-omega on the survival time and quality of life of cats with feline infectious peritonitis","volume":"21","author":"Ritz","year":"2007","journal-title":"J. Vet. Intern. Med."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1","DOI":"10.2460\/ajvr.23.10.0221","article-title":"Quality assessment and characterization of unregulated antiviral drugs for feline infectious peritonitis: Implications for treatment, safety, and efficacy","volume":"85","author":"Mulligan","year":"2024","journal-title":"Am. J. Vet. Res."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"489","DOI":"10.2460\/javma.23.08.0466","article-title":"Unlicensed antiviral products used for the at-home treatment of feline infectious peritonitis contain GS-441524 at significantly different amounts than advertised","volume":"262","author":"Kent","year":"2024","journal-title":"J. Am. Vet. Med. Assoc."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1098612x231183250","DOI":"10.1177\/1098612X231183250","article-title":"Long-term follow-up of cats in complete remission after treatment of feline infectious peritonitis with oral GS-441524","volume":"25","author":"Zwicklbauer","year":"2023","journal-title":"J. Feline Med. Surg."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Cosaro, E., Pires, J., Castillo, D., Murphy, B.G., and Reagan, K.L. (2023). Efficacy of Oral Remdesivir Compared to GS-441524 for Treatment of Cats with Naturally Occurring Effusive Feline Infectious Peritonitis: A Blinded, Non-Inferiority Study. Viruses, 15.","DOI":"10.3390\/v15081680"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Zuzzi-Krebitz, A.M., Buchta, K., Bergmann, M., Krentz, D., Zwicklbauer, K., Dorsch, R., Wess, G., Fischer, A., Matiasek, K., and Honl, A. (2024). Short Treatment of 42 Days with Oral GS-441524 Results in Equal Efficacy as the Recommended 84-Day Treatment in Cats Suffering from Feline Infectious Peritonitis with Effusion-A Prospective Randomized Controlled Study. Viruses, 16.","DOI":"10.3390\/v16071144"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Negash, R., Li, E., Jacque, N., Novicoff, W., and Evans, S.J.M. (2024). Owner experience and veterinary involvement with unlicensed GS-441524 treatment of feline infectious peritonitis: A prospective cohort study. Front. Vet. Sci., 11.","DOI":"10.3389\/fvets.2024.1377207"},{"key":"ref_36","unstructured":"Federation of Veterinarians of Europe (2025, May 19). Finally a FIP Treatment Opportunity in the EU! 2024. Available online: https:\/\/fve.org\/finally-a-fip-treatment-opportunity-in-eu\/."}],"container-title":["Pathogens"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-0817\/14\/7\/717\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T18:12:43Z","timestamp":1760033563000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-0817\/14\/7\/717"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,7,19]]},"references-count":36,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2025,7]]}},"alternative-id":["pathogens14070717"],"URL":"https:\/\/doi.org\/10.3390\/pathogens14070717","relation":{},"ISSN":["2076-0817"],"issn-type":[{"value":"2076-0817","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,7,19]]}}}