{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,18]],"date-time":"2026-03-18T17:00:30Z","timestamp":1773853230535,"version":"3.50.1"},"reference-count":21,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2026,3,18]],"date-time":"2026-03-18T00:00:00Z","timestamp":1773792000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Reports"],"abstract":"<jats:p>Background and Clinical Significance: Ensitrelvir is an oral inhibitor of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease (3CL pro). Compared with remdesivir and molnupiravir, ensitrelvir achieves higher rates of SARS-CoV-2 antigen clearance and a more favorable viral shedding profile. Case Presentation: A 67-year-old Japanese man with follicular lymphoma had received obinutuzumab plus bendamustine, followed by obinutuzumab maintenance therapy. Hypogammaglobulinemia and profound B-cell depletion persisted for more than 1 year after the final maintenance dose. Three months prior to the current admission, the patient developed coronavirus disease 2019 (COVID-19) and was treated with a 10-day course of remdesivir and dexamethasone. The patient subsequently presented with recurrent COVID-19 pneumonia. Treatment with remdesivir and dexamethasone did not result in clinical improvement, and the SARS-CoV-2 antigen level increased despite adjunctive intravenous immunoglobulin. After ensitrelvir was added to remdesivir, the SARS-CoV-2 antigen levels declined rapidly, and clinical parameters, including fever, inflammatory markers (C-reactive protein), and oxygenation, improved promptly, allowing for discharge. Conclusions: Ensitrelvir may be an effective therapeutic option for the treatment of persistent or refractory COVID-19 in immunocompromised patients. Clinicians should recognize that patients treated with obinutuzumab may remain immunosuppressed for several years after therapy.<\/jats:p>","DOI":"10.3390\/reports9010089","type":"journal-article","created":{"date-parts":[[2026,3,18]],"date-time":"2026-03-18T10:11:12Z","timestamp":1773828672000},"page":"89","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Successful Treatment of Persistent and Relapsing COVID-19 with Ensitrelvir in a Patient with Obinutuzumab-Induced Long-Term B-Cell Depletion: A Case Report"],"prefix":"10.3390","volume":"9","author":[{"given":"Yoshitaka","family":"Haino","sequence":"first","affiliation":[{"name":"Department of Internal Medicine, Hyogo Prefectural Tamba Medical Center, 2002-7 Iso, Hikami-cho, Tamba 669-3495, Hyogo, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3120-6605","authenticated-orcid":false,"given":"Tsuneaki","family":"Kenzaka","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, Hyogo Prefectural Tamba Medical Center, 2002-7 Iso, Hikami-cho, Tamba 669-3495, Hyogo, Japan"},{"name":"Division of Community Medicine and Career Development, Kobe University Graduate School of Medicine, 2-1-5 Arata-cho, Hyogo-ku, Kobe 652-0032, Hyogo, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0164-7629","authenticated-orcid":false,"given":"Tomohiro","family":"Hayashi","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, Hyogo Prefectural Tamba Medical Center, 2002-7 Iso, Hikami-cho, Tamba 669-3495, Hyogo, Japan"},{"name":"Division of Community Medicine and Career Development, Kobe University Graduate School of Medicine, 2-1-5 Arata-cho, Hyogo-ku, Kobe 652-0032, Hyogo, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2511-7857","authenticated-orcid":false,"given":"Kimikazu","family":"Yakushijin","sequence":"additional","affiliation":[{"name":"Division of Medical Oncology\/Hematology, Department of Medicine, Kobe University Hospital and Graduate School of Medicine, Kobe 650-0017, Hyogo, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,18]]},"reference":[{"key":"ref_1","unstructured":"World Health Organization (2023, October 02). 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