{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,25]],"date-time":"2026-04-25T13:26:39Z","timestamp":1777123599058,"version":"3.51.4"},"reference-count":20,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2025,5,13]],"date-time":"2025-05-13T00:00:00Z","timestamp":1747094400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Yvonne Jacob Foundation"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Viruses"],"abstract":"<jats:p>A treatment-experienced, highly adherent person living with HIV for over 25 years developed resistance mutations against all four major ART classes, including bictegravir (BIC). This led to viral failure on a quadruple regimen including BIC and doravirine (DOR). Resistance emergence was associated with M184V, thymidine analog mutations (TAMs), NNRTI mutations (108I, 234I, 318F), and INSTI mutations (T97A, G140S, Q148H, G149A), likely driven by suboptimal BIC levels due to divalent cation interactions. During a two-month ART interruption, the resistant virus was rapidly replaced by an ancient wild-type strain. Despite resistance to all four ART classes, a genotype-adapted salvage regimen, including fostemsavir, achieved viral suppression within seven months.<\/jats:p>","DOI":"10.3390\/v17050699","type":"journal-article","created":{"date-parts":[[2025,5,13]],"date-time":"2025-05-13T11:31:49Z","timestamp":1747135909000},"page":"699","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Emergence of Bictegravir Resistance in a Treatment-Experienced PWH on Functional Monotherapy and Rapid Replacement by an Ancient Wild-Type Strain Following Transient Treatment Interruption"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0944-2609","authenticated-orcid":false,"given":"Pietro B.","family":"Far\u00e9","sequence":"first","affiliation":[{"name":"Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, 8091 Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gabriela","family":"Ziltener","sequence":"additional","affiliation":[{"name":"Institute of Medical Virology, University of Zurich, 8057 Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5516-0306","authenticated-orcid":false,"given":"Judith","family":"Bergad\u00e0 Pijuan","sequence":"additional","affiliation":[{"name":"Institute of Medical Virology, University of Zurich, 8057 Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5566-8628","authenticated-orcid":false,"given":"Irene A.","family":"Abela","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, 8091 Zurich, Switzerland"},{"name":"Institute of Medical Virology, University of Zurich, 8057 Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Britta L.","family":"Hirsch","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, 8091 Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0384-0000","authenticated-orcid":false,"given":"Michael","family":"Huber","sequence":"additional","affiliation":[{"name":"Institute of Medical Virology, University of Zurich, 8057 Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Johannes","family":"Nemeth","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, 8091 Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1142-6723","authenticated-orcid":false,"given":"Huldrych F.","family":"G\u00fcnthard","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, 8091 Zurich, Switzerland"},{"name":"Institute of Medical Virology, University of Zurich, 8057 Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,5,13]]},"reference":[{"key":"ref_1","first-page":"33","article-title":"Cohort Profile Update: The Swiss HIV Cohort Study (SHCS)","volume":"51","author":"Scherrer","year":"2022","journal-title":"Leuk. 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