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Persistent SARS-CoV-2 infection in patients with secondary antibody deficiency: successful clearance following combination casirivimab and imdevimab (REGN-COV2) monoclonal antibody therapy

Lookup NU author(s): Dr Yusri Taha, Dr Ewan Hunter, Dr Wendy Osborne, Dr Matthew BashtonORCiD, Dr Darren Smith, Dr Matthias Schmid, Dr Christopher DuncanORCiD



This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).


© 2021, The Author(s).Background: There is growing evidence that antibody responses play a role in the resolution of SARS-CoV-2 infection. Patients with primary or secondary antibody deficiency are at increased risk of persistent infection. This challenging clinical scenario is associated with adverse patient outcome and potentially creates an ecological niche for the evolution of novel SARS-CoV-2 variants with immune evasion capacity. Case reports and/or series have implied a therapeutic role for convalescent plasma (CP) to secure virological clearance, although concerns have been raised about the effectiveness of CP and its potential to drive viral evolution, and it has largely been withdrawn from clinical use in the UK. Case presentation: We report two cases in which persistent SARS-CoV-2 infection was cleared following administration of the monoclonal antibody combination casirivimab and imdevimab (REGN-COV2, Ronapreve). A 55-year-old male with follicular lymphoma, treated with B cell depleting therapy, developed SARS-CoV-2 infection in September 2020 which then persisted for over 200 days. He was hospitalised on four occasions with COVID-19 and suffered debilitating fatigue and malaise throughout. There was no clinical response to antiviral therapy with remdesivir or CP, and SARS-CoV-2 was consistently detected in nasopharyngeal swabs. Intrahost evolution of several spike variants of uncertain significance was identified by viral sequence analysis. Delivery of REGN-COV2, in combination with remdesivir, was associated with clinical improvement and viral clearance within 6 days, which was sustained for over 150 days despite immunotherapy for relapsed follicular lymphoma. The second case, a 68-year-old female with chronic lymphocytic leukaemia on ibrutinib, also developed persistent SARS-CoV-2 infection. Despite a lack of response to remdesivir, infection promptly cleared following REGN-COV2 in combination with remdesivir, accompanied by resolution of inflammation and full clinical recovery that has been maintained for over 290 days. Conclusions: These cases highlight the potential benefit of REGN-COV2 as therapy for persistent SARS-CoV-2 infection in antibody deficient individuals, including after failure of CP treatment. Formal clinical studies are warranted to assess the effectiveness of REGN-COV2 in antibody-deficient patients, especially in light of the emergence of variants of concern, such as Omicron, that appear to evade REGN-COV2 neutralisation.

Publication metadata

Author(s): Taha Y, Wardle H, Evans AB, Hunter ER, Marr H, Osborne W, Bashton M, Smith D, Burton-Fanning S, Schmid ML, Duncan CJA

Publication type: Article

Publication status: Published

Journal: Annals of Clinical Microbiology and Antimicrobials

Year: 2021

Volume: 20

Issue: 1

Print publication date: 01/12/2021

Online publication date: 30/12/2021

Acceptance date: 22/12/2021

Date deposited: 14/01/2022

ISSN (electronic): 1476-0711

Publisher: BioMed Central Ltd


DOI: 10.1186/s12941-021-00491-2


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Funder referenceFunder name
CJAD is funded by the Barbour Foundation, the UK-Coronavirus Immunology Consortium and a Wellcome Clinical Research Career Development Fellowship (211153/Z/18/Z).
Formal funding was not required for this case report.